draft-ietf-idr-ls-distribution-13.txt   rfc7752.txt 
Inter-Domain Routing H. Gredler, Ed. Internet Engineering Task Force (IETF) H. Gredler, Ed.
Internet-Draft Private Contributor Request for Comments: 7752 Individual Contributor
Intended status: Standards Track J. Medved Category: Standards Track J. Medved
Expires: April 18, 2016 S. Previdi ISSN: 2070-1721 S. Previdi
Cisco Systems, Inc. Cisco Systems, Inc.
A. Farrel A. Farrel
Juniper Networks, Inc. Juniper Networks, Inc.
S. Ray S. Ray
October 16, 2015 March 2016
North-Bound Distribution of Link-State and TE Information using BGP North-Bound Distribution of Link-State and Traffic Engineering (TE)
draft-ietf-idr-ls-distribution-13 Information Using BGP
Abstract Abstract
In a number of environments, a component external to a network is In a number of environments, a component external to a network is
called upon to perform computations based on the network topology and called upon to perform computations based on the network topology and
current state of the connections within the network, including current state of the connections within the network, including
traffic engineering information. This is information typically Traffic Engineering (TE) information. This is information typically
distributed by IGP routing protocols within the network. distributed by IGP routing protocols within the network.
This document describes a mechanism by which links state and traffic This document describes a mechanism by which link-state and TE
engineering information can be collected from networks and shared information can be collected from networks and shared with external
with external components using the BGP routing protocol. This is components using the BGP routing protocol. This is achieved using a
achieved using a new BGP Network Layer Reachability Information new BGP Network Layer Reachability Information (NLRI) encoding
(NLRI) encoding format. The mechanism is applicable to physical and format. The mechanism is applicable to physical and virtual IGP
virtual IGP links. The mechanism described is subject to policy links. The mechanism described is subject to policy control.
control.
Applications of this technique include Application Layer Traffic
Optimization (ALTO) servers, and Path Computation Elements (PCEs).
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", Applications of this technique include Application-Layer Traffic
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this Optimization (ALTO) servers and Path Computation Elements (PCEs).
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on April 18, 2016. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7752.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................3
2. Motivation and Applicability . . . . . . . . . . . . . . . . 5 1.1. Requirements Language ......................................5
2.1. MPLS-TE with PCE . . . . . . . . . . . . . . . . . . . . 5 2. Motivation and Applicability ....................................5
2.2. ALTO Server Network API . . . . . . . . . . . . . . . . . 6 2.1. MPLS-TE with PCE ...........................................5
3. Carrying Link State Information in BGP . . . . . . . . . . . 7 2.2. ALTO Server Network API ....................................6
3.1. TLV Format . . . . . . . . . . . . . . . . . . . . . . . 7 3. Carrying Link-State Information in BGP ..........................7
3.2. The Link-State NLRI . . . . . . . . . . . . . . . . . . . 8 3.1. TLV Format .................................................8
3.2.1. Node Descriptors . . . . . . . . . . . . . . . . . . 12 3.2. The Link-State NLRI ........................................8
3.2.2. Link Descriptors . . . . . . . . . . . . . . . . . . 16 3.2.1. Node Descriptors ...................................12
3.2.3. Prefix Descriptors . . . . . . . . . . . . . . . . . 17 3.2.2. Link Descriptors ...................................16
3.3. The BGP-LS Attribute . . . . . . . . . . . . . . . . . . 19 3.2.3. Prefix Descriptors .................................18
3.3.1. Node Attribute TLVs . . . . . . . . . . . . . . . . . 19 3.3. The BGP-LS Attribute ......................................19
3.3.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . 23 3.3.1. Node Attribute TLVs ................................20
3.3.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . 28 3.3.2. Link Attribute TLVs ................................23
3.4. BGP Next Hop Information . . . . . . . . . . . . . . . . 31 3.3.3. Prefix Attribute TLVs ..............................28
3.5. Inter-AS Links . . . . . . . . . . . . . . . . . . . . . 32 3.4. BGP Next-Hop Information ..................................31
3.6. Router-ID Anchoring Example: ISO Pseudonode . . . . . . . 32 3.5. Inter-AS Links ............................................32
3.7. Router-ID Anchoring Example: OSPF Pseudonode . . . . . . 33 3.6. Router-ID Anchoring Example: ISO Pseudonode ...............32
3.8. Router-ID Anchoring Example: OSPFv2 to IS-IS Migration . 34 3.7. Router-ID Anchoring Example: OSPF Pseudonode ..............33
4. Link to Path Aggregation . . . . . . . . . . . . . . . . . . 34 3.8. Router-ID Anchoring Example: OSPFv2 to IS-IS Migration ....34
4.1. Example: No Link Aggregation . . . . . . . . . . . . . . 35 4. Link to Path Aggregation .......................................34
4.2. Example: ASBR to ASBR Path Aggregation . . . . . . . . . 35 4.1. Example: No Link Aggregation ..............................35
4.3. Example: Multi-AS Path Aggregation . . . . . . . . . . . 36 4.2. Example: ASBR to ASBR Path Aggregation ....................35
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 36 4.3. Example: Multi-AS Path Aggregation ........................36
5.1. Guidance for Designated Experts . . . . . . . . . . . . . 37 5. IANA Considerations ............................................36
6. Manageability Considerations . . . . . . . . . . . . . . . . 37 5.1. Guidance for Designated Experts ...........................37
6.1. Operational Considerations . . . . . . . . . . . . . . . 37 6. Manageability Considerations ...................................38
6.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 37 6.1. Operational Considerations ................................38
6.1.2. Installation and Initial Setup . . . . . . . . . . . 38 6.1.1. Operations .........................................38
6.1.3. Migration Path . . . . . . . . . . . . . . . . . . . 38 6.1.2. Installation and Initial Setup .....................38
6.1.4. Requirements on Other Protocols and Functional 6.1.3. Migration Path .....................................38
Components . . . . . . . . . . . . . . . . . . . . . 38 6.1.4. Requirements on Other Protocols and
6.1.5. Impact on Network Operation . . . . . . . . . . . . . 38 Functional Components ..............................38
6.1.6. Verifying Correct Operation . . . . . . . . . . . . . 38 6.1.5. Impact on Network Operation ........................38
6.2. Management Considerations . . . . . . . . . . . . . . . . 39 6.1.6. Verifying Correct Operation ........................39
6.2.1. Management Information . . . . . . . . . . . . . . . 39 6.2. Management Considerations .................................39
6.2.2. Fault Management . . . . . . . . . . . . . . . . . . 39 6.2.1. Management Information .............................39
6.2.3. Configuration Management . . . . . . . . . . . . . . 39 6.2.2. Fault Management ...................................39
6.2.4. Accounting Management . . . . . . . . . . . . . . . . 40 6.2.3. Configuration Management ...........................40
6.2.5. Performance Management . . . . . . . . . . . . . . . 40 6.2.4. Accounting Management ..............................40
6.2.6. Security Management . . . . . . . . . . . . . . . . . 40 6.2.5. Performance Management .............................40
7. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . . . 40 6.2.6. Security Management ................................41
8. Security Considerations . . . . . . . . . . . . . . . . . . . 42 7. TLV/Sub-TLV Code Points Summary ................................41
9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 43 8. Security Considerations ........................................42
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 43 9. References .....................................................43
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 43 9.1. Normative References ......................................43
11.1. Normative References . . . . . . . . . . . . . . . . . . 43 9.2. Informative References ....................................45
11.2. Informative References . . . . . . . . . . . . . . . . . 45 Acknowledgements ..................................................47
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 47 Contributors ......................................................47
Authors' Addresses ................................................48
1. Introduction 1. Introduction
The contents of a Link State Database (LSDB) or of an IGP's Traffic The contents of a Link-State Database (LSDB) or of an IGP's Traffic
Engineering Database (TED) describe only the links and nodes within Engineering Database (TED) describe only the links and nodes within
an IGP area. Some applications, such as end-to-end Traffic an IGP area. Some applications, such as end-to-end Traffic
Engineering (TE), would benefit from visibility outside one area or Engineering (TE), would benefit from visibility outside one area or
Autonomous System (AS) in order to make better decisions. Autonomous System (AS) in order to make better decisions.
The IETF has defined the Path Computation Element (PCE) [RFC4655] as The IETF has defined the Path Computation Element (PCE) [RFC4655] as
a mechanism for achieving the computation of end-to-end TE paths that a mechanism for achieving the computation of end-to-end TE paths that
cross the visibility of more than one TED or which require CPU- cross the visibility of more than one TED or that require CPU-
intensive or coordinated computations. The IETF has also defined the intensive or coordinated computations. The IETF has also defined the
ALTO Server [RFC5693] as an entity that generates an abstracted ALTO server [RFC5693] as an entity that generates an abstracted
network topology and provides it to network-aware applications. network topology and provides it to network-aware applications.
Both a PCE and an ALTO Server need to gather information about the Both a PCE and an ALTO server need to gather information about the
topologies and capabilities of the network in order to be able to topologies and capabilities of the network in order to be able to
fulfill their function. fulfill their function.
This document describes a mechanism by which Link State and TE This document describes a mechanism by which link-state and TE
information can be collected from networks and shared with external information can be collected from networks and shared with external
components using the BGP routing protocol [RFC4271]. This is components using the BGP routing protocol [RFC4271]. This is
achieved using a new BGP Network Layer Reachability Information achieved using a new BGP Network Layer Reachability Information
(NLRI) encoding format. The mechanism is applicable to physical and (NLRI) encoding format. The mechanism is applicable to physical and
virtual links. The mechanism described is subject to policy control. virtual links. The mechanism described is subject to policy control.
A router maintains one or more databases for storing link-state A router maintains one or more databases for storing link-state
information about nodes and links in any given area. Link attributes information about nodes and links in any given area. Link attributes
stored in these databases include: local/remote IP addresses, local/ stored in these databases include: local/remote IP addresses, local/
remote interface identifiers, link metric and TE metric, link remote interface identifiers, link metric and TE metric, link
bandwidth, reservable bandwidth, per CoS class reservation state, bandwidth, reservable bandwidth, per Class-of-Service (CoS) class
preemption and Shared Risk Link Groups (SRLG). The router's BGP reservation state, preemption, and Shared Risk Link Groups (SRLGs).
process can retrieve topology from these LSDBs and distribute it to a The router's BGP process can retrieve topology from these LSDBs and
consumer, either directly or via a peer BGP Speaker (typically a distribute it to a consumer, either directly or via a peer BGP
dedicated Route Reflector), using the encoding specified in this speaker (typically a dedicated Route Reflector), using the encoding
document. specified in this document.
The collection of Link State and TE link state information and its The collection of link-state and TE information and its distribution
distribution to consumers is shown in the following figure. to consumers is shown in the following figure.
+-----------+ +-----------+
| Consumer | | Consumer |
+-----------+ +-----------+
^ ^
| |
+-----------+ +-----------+
| BGP | +-----------+ | BGP | +-----------+
| Speaker | | Consumer | | Speaker | | Consumer |
+-----------+ +-----------+ +-----------+ +-----------+
skipping to change at page 4, line 43 skipping to change at page 4, line 40
+---------------+ | +-------------------+ | +---------------+ | +-------------------+ |
| | | | | | | |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
| BGP | | BGP | | BGP | | BGP | | BGP | | BGP |
| Speaker | | Speaker | . . . | Speaker | | Speaker | | Speaker | . . . | Speaker |
+-----------+ +-----------+ +-----------+ +-----------+ +-----------+ +-----------+
^ ^ ^ ^ ^ ^
| | | | | |
IGP IGP IGP IGP IGP IGP
Figure 1: TE Link State info collection Figure 1: Collection of Link-State and TE Information
A BGP Speaker may apply configurable policy to the information that A BGP speaker may apply configurable policy to the information that
it distributes. Thus, it may distribute the real physical topology it distributes. Thus, it may distribute the real physical topology
from the LSDB or the TED. Alternatively, it may create an abstracted from the LSDB or the TED. Alternatively, it may create an abstracted
topology, where virtual, aggregated nodes are connected by virtual topology, where virtual, aggregated nodes are connected by virtual
paths. Aggregated nodes can be created, for example, out of multiple paths. Aggregated nodes can be created, for example, out of multiple
routers in a POP. Abstracted topology can also be a mix of physical routers in a Point of Presence (POP). Abstracted topology can also
and virtual nodes and physical and virtual links. Furthermore, the be a mix of physical and virtual nodes and physical and virtual
BGP Speaker can apply policy to determine when information is updated links. Furthermore, the BGP speaker can apply policy to determine
to the consumer so that there is reduction of information flow from when information is updated to the consumer so that there is a
the network to the consumers. Mechanisms through which topologies reduction of information flow from the network to the consumers.
can be aggregated or virtualized are outside the scope of this Mechanisms through which topologies can be aggregated or virtualized
document are outside the scope of this document
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Motivation and Applicability 2. Motivation and Applicability
This section describes use cases from which the requirements can be This section describes use cases from which the requirements can be
derived. derived.
2.1. MPLS-TE with PCE 2.1. MPLS-TE with PCE
As described in [RFC4655] a PCE can be used to compute MPLS-TE paths As described in [RFC4655], a PCE can be used to compute MPLS-TE paths
within a "domain" (such as an IGP area) or across multiple domains within a "domain" (such as an IGP area) or across multiple domains
(such as a multi-area AS, or multiple ASes). (such as a multi-area AS or multiple ASes).
o Within a single area, the PCE offers enhanced computational power o Within a single area, the PCE offers enhanced computational power
that may not be available on individual routers, sophisticated that may not be available on individual routers, sophisticated
policy control and algorithms, and coordination of computation policy control and algorithms, and coordination of computation
across the whole area. across the whole area.
o If a router wants to compute a MPLS-TE path across IGP areas, then o If a router wants to compute a MPLS-TE path across IGP areas, then
its own TED lacks visibility of the complete topology. That means its own TED lacks visibility of the complete topology. That means
that the router cannot determine the end-to-end path, and cannot that the router cannot determine the end-to-end path and cannot
even select the right exit router (Area Border Router - ABR) for even select the right exit router (Area Border Router (ABR)) for
an optimal path. This is an issue for large-scale networks that an optimal path. This is an issue for large-scale networks that
need to segment their core networks into distinct areas, but still need to segment their core networks into distinct areas but still
want to take advantage of MPLS-TE. want to take advantage of MPLS-TE.
Previous solutions used per-domain path computation [RFC5152]. The Previous solutions used per-domain path computation [RFC5152]. The
source router could only compute the path for the first area because source router could only compute the path for the first area because
the router only has full topological visibility for the first area the router only has full topological visibility for the first area
along the path, but not for subsequent areas. Per-domain path along the path, but not for subsequent areas. Per-domain path
computation uses a technique called "loose-hop-expansion" [RFC3209], computation uses a technique called "loose-hop-expansion" [RFC3209]
and selects the exit ABR and other ABRs or AS Border Routers (ASBRs) and selects the exit ABR and other ABRs or AS Border Routers (ASBRs)
using the IGP computed shortest path topology for the remainder of using the IGP-computed shortest path topology for the remainder of
the path. This may lead to sub-optimal paths, makes alternate/back- the path. This may lead to sub-optimal paths, makes alternate/back-
up path computation hard, and might result in no TE path being found up path computation hard, and might result in no TE path being found
when one really does exist. when one really does exist.
The PCE presents a computation server that may have visibility into The PCE presents a computation server that may have visibility into
more than one IGP area or AS, or may cooperate with other PCEs to more than one IGP area or AS, or may cooperate with other PCEs to
perform distributed path computation. The PCE obviously needs access perform distributed path computation. The PCE obviously needs access
to the TED for the area(s) it serves, but [RFC4655] does not describe to the TED for the area(s) it serves, but [RFC4655] does not describe
how this is achieved. Many implementations make the PCE a passive how this is achieved. Many implementations make the PCE a passive
participant in the IGP so that it can learn the latest state of the participant in the IGP so that it can learn the latest state of the
network, but this may be sub-optimal when the network is subject to a network, but this may be sub-optimal when the network is subject to a
high degree of churn, or when the PCE is responsible for multiple high degree of churn or when the PCE is responsible for multiple
areas. areas.
The following figure shows how a PCE can get its TED information The following figure shows how a PCE can get its TED information
using the mechanism described in this document. using the mechanism described in this document.
+----------+ +---------+ +----------+ +---------+
| ----- | | BGP | | ----- | | BGP |
| | TED |<-+-------------------------->| Speaker | | | TED |<-+-------------------------->| Speaker |
| ----- | TED synchronization | | | ----- | TED synchronization | |
| | | mechanism: +---------+ | | | mechanism: +---------+
skipping to change at page 6, line 30 skipping to change at page 6, line 34
+----------+ +----------+
^ ^
| Request/ | Request/
| Response | Response
v v
Service +----------+ Signaling +----------+ Service +----------+ Signaling +----------+
Request | Head-End | Protocol | Adjacent | Request | Head-End | Protocol | Adjacent |
-------->| Node |<------------>| Node | -------->| Node |<------------>| Node |
+----------+ +----------+ +----------+ +----------+
Figure 2: External PCE node using a TED synchronization mechanism Figure 2: External PCE Node Using a TED Synchronization Mechanism
The mechanism in this document allows the necessary TED information The mechanism in this document allows the necessary TED information
to be collected from the IGP within the network, filtered according to be collected from the IGP within the network, filtered according
to configurable policy, and distributed to the PCE as necessary. to configurable policy, and distributed to the PCE as necessary.
2.2. ALTO Server Network API 2.2. ALTO Server Network API
An ALTO Server [RFC5693] is an entity that generates an abstracted An ALTO server [RFC5693] is an entity that generates an abstracted
network topology and provides it to network-aware applications over a network topology and provides it to network-aware applications over a
web service based API. Example applications are p2p clients or web-service-based API. Example applications are peer-to-peer (P2P)
trackers, or CDNs. The abstracted network topology comes in the form clients or trackers, or Content Distribution Networks (CDNs). The
of two maps: a Network Map that specifies allocation of prefixes to abstracted network topology comes in the form of two maps: a Network
Partition Identifiers (PIDs), and a Cost Map that specifies the cost Map that specifies allocation of prefixes to Partition Identifiers
between PIDs listed in the Network Map. For more details, see (PIDs), and a Cost Map that specifies the cost between PIDs listed in
[RFC7285]. the Network Map. For more details, see [RFC7285].
ALTO abstract network topologies can be auto-generated from the ALTO abstract network topologies can be auto-generated from the
physical topology of the underlying network. The generation would physical topology of the underlying network. The generation would
typically be based on policies and rules set by the operator. Both typically be based on policies and rules set by the operator. Both
prefix and TE data are required: prefix data is required to generate prefix and TE data are required: prefix data is required to generate
ALTO Network Maps, TE (topology) data is required to generate ALTO ALTO Network Maps, and TE (topology) data is required to generate
Cost Maps. Prefix data is carried and originated in BGP, TE data is ALTO Cost Maps. Prefix data is carried and originated in BGP, and TE
originated and carried in an IGP. The mechanism defined in this data is originated and carried in an IGP. The mechanism defined in
document provides a single interface through which an ALTO Server can this document provides a single interface through which an ALTO
retrieve all the necessary prefix and network topology data from the server can retrieve all the necessary prefix and network topology
underlying network. Note an ALTO Server can use other mechanisms to data from the underlying network. Note that an ALTO server can use
get network data, for example, peering with multiple IGP and BGP other mechanisms to get network data, for example, peering with
Speakers. multiple IGP and BGP speakers.
The following figure shows how an ALTO Server can get network The following figure shows how an ALTO server can get network
topology information from the underlying network using the mechanism topology information from the underlying network using the mechanism
described in this document. described in this document.
+--------+ +--------+
| Client |<--+ | Client |<--+
+--------+ | +--------+ |
| ALTO +--------+ BGP with +---------+ | ALTO +--------+ BGP with +---------+
+--------+ | Protocol | ALTO | Link-State NLRI | BGP | +--------+ | Protocol | ALTO | Link-State NLRI | BGP |
| Client |<--+------------| Server |<----------------| Speaker | | Client |<--+------------| Server |<----------------| Speaker |
+--------+ | | | | | +--------+ | | | | |
| +--------+ +---------+ | +--------+ +---------+
+--------+ | +--------+ |
| Client |<--+ | Client |<--+
+--------+ +--------+
Figure 3: ALTO Server using network topology information Figure 3: ALTO Server Using Network Topology Information
3. Carrying Link State Information in BGP 3. Carrying Link-State Information in BGP
This specification contains two parts: definition of a new BGP NLRI This specification contains two parts: definition of a new BGP NLRI
that describes links, nodes and prefixes comprising IGP link state that describes links, nodes, and prefixes comprising IGP link-state
information, and definition of a new BGP path attribute (BGP-LS information and definition of a new BGP path attribute (BGP-LS
attribute) that carries link, node and prefix properties and attribute) that carries link, node, and prefix properties and
attributes, such as the link and prefix metric or auxiliary Router- attributes, such as the link and prefix metric or auxiliary Router-
IDs of nodes, etc. IDs of nodes, etc.
It is desired to keep the dependencies on the protocol source of this It is desirable to keep the dependencies on the protocol source of
attributes to a minimum and represent any content in an IGP neutral this attribute to a minimum and represent any content in an IGP-
way, such that applications which do want to learn about a Link-state neutral way, such that applications that want to learn about a link-
topology do not need to know about any OSPF or IS-IS protocol state topology do not need to know about any OSPF or IS-IS protocol
specifics. specifics.
3.1. TLV Format 3.1. TLV Format
Information in the new Link-State NLRIs and attributes is encoded in Information in the new Link-State NLRIs and attributes is encoded in
Type/Length/Value triplets. The TLV format is shown in Figure 4. Type/Length/Value triplets. The TLV format is shown in Figure 4.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Value (variable) // // Value (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: TLV format Figure 4: TLV Format
The Length field defines the length of the value portion in octets The Length field defines the length of the value portion in octets
(thus a TLV with no value portion would have a length of zero). The (thus, a TLV with no value portion would have a length of zero). The
TLV is not padded to four-octet alignment. Unrecognized types MUST TLV is not padded to 4-octet alignment. Unrecognized types MUST be
be preserved and propagated. In order to compare NLRIs with unknown preserved and propagated. In order to compare NLRIs with unknown
TLVs all TLVs MUST be ordered in ascending order by TLV Type. If TLVs, all TLVs MUST be ordered in ascending order by TLV Type. If
there are more TLVs of the same type, then the TLVs MUST be ordered there are more TLVs of the same type, then the TLVs MUST be ordered
in ascending order of the TLV value within the TLVs with the same in ascending order of the TLV value within the TLVs with the same
type by treating the entire value field an opaque hexadecimal string type by treating the entire Value field as an opaque hexadecimal
and comparing leftmost octets first regardless of the length of the string and comparing leftmost octets first, regardless of the length
string. . All TLVs that are not specified as mandatory are of the string. All TLVs that are not specified as mandatory are
considered optional. considered optional.
3.2. The Link-State NLRI 3.2. The Link-State NLRI
The MP_REACH_NLRI and MP_UNREACH_NLRI attributes are BGP's containers The MP_REACH_NLRI and MP_UNREACH_NLRI attributes are BGP's containers
for carrying opaque information. Each Link-State NLRI describes for carrying opaque information. Each Link-State NLRI describes
either a node, a link or a prefix. either a node, a link, or a prefix.
All non-VPN link, node and prefix information SHALL be encoded using All non-VPN link, node, and prefix information SHALL be encoded using
AFI 16388 / SAFI 71. VPN link, node and prefix information SHALL be AFI 16388 / SAFI 71. VPN link, node, and prefix information SHALL be
encoded using AFI 16388 / SAFI TBD. encoded using AFI 16388 / SAFI 72.
In order for two BGP speakers to exchange Link-State NLRI, they MUST In order for two BGP speakers to exchange Link-State NLRI, they MUST
use BGP Capabilities Advertisement to ensure that they both are use BGP Capabilities Advertisement to ensure that they are both
capable of properly processing such NLRI. This is done as specified capable of properly processing such NLRI. This is done as specified
in [RFC4760], by using capability code 1 (multi-protocol BGP), with in [RFC4760], by using capability code 1 (multi-protocol BGP), with
AFI 16388 / SAFI 71 for BGP-LS, and AFI 16388 / SAFI TBD for BGP-LS- AFI 16388 / SAFI 71 for BGP-LS, and AFI 16388 / SAFI 72 for
VPN. BGP-LS-VPN.
The format of the Link-State NLRI is shown in the following figure. The format of the Link-State NLRI is shown in the following figures.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NLRI Type | Total NLRI Length | | NLRI Type | Total NLRI Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Link-State NLRI (variable) // // Link-State NLRI (variable) //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 9, line 31 skipping to change at page 9, line 33
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Route Distinguisher + + Route Distinguisher +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Link-State NLRI (variable) // // Link-State NLRI (variable) //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Link-State VPN AFI 16388 / SAFI TBD NLRI Format Figure 6: Link-State VPN AFI 16388 / SAFI 72 NLRI Format
The 'Total NLRI Length' field contains the cumulative length, in The Total NLRI Length field contains the cumulative length, in
octets, of rest of the NLRI not including the NLRI Type field or octets, of the rest of the NLRI, not including the NLRI Type field or
itself. For VPN applications, it also includes the length of the itself. For VPN applications, it also includes the length of the
Route Distinguisher. Route Distinguisher.
+------+---------------------------+ +------+---------------------------+
| Type | NLRI Type | | Type | NLRI Type |
+------+---------------------------+ +------+---------------------------+
| 1 | Node NLRI | | 1 | Node NLRI |
| 2 | Link NLRI | | 2 | Link NLRI |
| 3 | IPv4 Topology Prefix NLRI | | 3 | IPv4 Topology Prefix NLRI |
| 4 | IPv6 Topology Prefix NLRI | | 4 | IPv6 Topology Prefix NLRI |
skipping to change at page 10, line 16 skipping to change at page 10, line 20
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Protocol-ID | | Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | | Identifier |
| (64 bits) | | (64 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local Node Descriptors (variable) // // Local Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: The Node NLRI format Figure 7: The Node NLRI Format
The Link NLRI (NLRI Type = 2) is shown in the following figure. The Link NLRI (NLRI Type = 2) is shown in the following figure.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Protocol-ID | | Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | | Identifier |
| (64 bits) | | (64 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local Node Descriptors (variable) // // Local Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Remote Node Descriptors (variable) // // Remote Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Link Descriptors (variable) // // Link Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: The Link NLRI format Figure 8: The Link NLRI Format
The IPv4 and IPv6 Prefix NLRIs (NLRI Type = 3 and Type = 4) use the The IPv4 and IPv6 Prefix NLRIs (NLRI Type = 3 and Type = 4) use the
same format as shown in the following figure. same format, as shown in the following figure.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Protocol-ID | | Protocol-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | | Identifier |
| (64 bits) | | (64 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local Node Descriptor (variable) // // Local Node Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Prefix Descriptors (variable) // // Prefix Descriptors (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: The IPv4/IPv6 Topology Prefix NLRI format Figure 9: The IPv4/IPv6 Topology Prefix NLRI Format
The 'Protocol-ID' field can contain one of the following values: The Protocol-ID field can contain one of the following values:
+-------------+----------------------------------+ +-------------+----------------------------------+
| Protocol-ID | NLRI information source protocol | | Protocol-ID | NLRI information source protocol |
+-------------+----------------------------------+ +-------------+----------------------------------+
| 1 | IS-IS Level 1 | | 1 | IS-IS Level 1 |
| 2 | IS-IS Level 2 | | 2 | IS-IS Level 2 |
| 3 | OSPFv2 | | 3 | OSPFv2 |
| 4 | Direct | | 4 | Direct |
| 5 | Static configuration | | 5 | Static configuration |
| 6 | OSPFv3 | | 6 | OSPFv3 |
+-------------+----------------------------------+ +-------------+----------------------------------+
Table 2: Protocol Identifiers Table 2: Protocol Identifiers
The 'Direct' and 'Static configuration' protocol types SHOULD be used The 'Direct' and 'Static configuration' protocol types SHOULD be used
when BGP-LS is sourcing local information. For all information, when BGP-LS is sourcing local information. For all information
derived from other protocols the corresponding protocol-ID MUST be derived from other protocols, the corresponding Protocol-ID MUST be
used. If BGP-LS has got direct access to interface information and used. If BGP-LS has direct access to interface information and wants
wants to advertise a local link then the protocol-ID 'Direct' SHOULD to advertise a local link, then the Protocol-ID 'Direct' SHOULD be
be used. For modeling virtual links, like described in Section 4 the used. For modeling virtual links, such as described in Section 4,
protocol-ID 'Static configuration' SHOULD be used. the Protocol-ID 'Static configuration' SHOULD be used.
Both OSPF and IS-IS MAY run multiple routing protocol instances over Both OSPF and IS-IS MAY run multiple routing protocol instances over
the same link. See [RFC6822] and [RFC6549]. These instances define the same link. See [RFC6822] and [RFC6549]. These instances define
independent "routing universes". The 64-Bit 'Identifier' field is independent "routing universes". The 64-bit Identifier field is used
used to identify the "routing universe" where the NLRI belongs. The to identify the routing universe where the NLRI belongs. The NLRIs
NLRIs representing Link-state objects (nodes, links or prefixes) from representing link-state objects (nodes, links, or prefixes) from the
the same routing universe MUST have the same 'Identifier' value. same routing universe MUST have the same 'Identifier' value. NLRIs
NLRIs with different 'Identifier' values MUST be considered to be with different 'Identifier' values MUST be considered to be from
from different routing universes. Table 3 lists the 'Identifier' different routing universes. Table 3 lists the 'Identifier' values
values that are defined as well-known in this draft. that are defined as well-known in this document.
+------------+----------------------------------+ +------------+----------------------------------+
| Identifier | Routing Universe | | Identifier | Routing Universe |
+------------+----------------------------------+ +------------+----------------------------------+
| 0 | Default Layer 3 Routing topology | | 0 | Default Layer 3 Routing topology |
| 1-31 | Reserved |
+------------+----------------------------------+ +------------+----------------------------------+
Table 3: Well-known Instance Identifiers Table 3: Well-Known Instance Identifiers
If a given Protocol does not support multiple routing universes then If a given protocol does not support multiple routing universes, then
it SHOULD set the 'Identifier' field according to Table 3. However it SHOULD set the Identifier field according to Table 3. However, an
an implementation MAY make the 'Identifier' configurable, for a given implementation MAY make the 'Identifier' configurable for a given
protocol. protocol.
Each Node Descriptor and Link Descriptor consists of one or more TLVs Each Node Descriptor and Link Descriptor consists of one or more
described in the following sections. TLVs, as described in the following sections.
3.2.1. Node Descriptors 3.2.1. Node Descriptors
Each link is anchored by a pair of Router-IDs that are used by the Each link is anchored by a pair of Router-IDs that are used by the
underlying IGP, namely, 48 Bit ISO System-ID for IS-IS and 32 bit underlying IGP, namely, a 48-bit ISO System-ID for IS-IS and a 32-bit
Router-ID for OSPFv2 and OSPFv3. An IGP may use one or more Router-ID for OSPFv2 and OSPFv3. An IGP may use one or more
additional auxiliary Router-IDs, mainly for traffic engineering additional auxiliary Router-IDs, mainly for Traffic Engineering
purposes. For example, IS-IS may have one or more IPv4 and IPv6 TE purposes. For example, IS-IS may have one or more IPv4 and IPv6 TE
Router-IDs [RFC5305], [RFC6119]. These auxiliary Router-IDs MUST be Router-IDs [RFC5305] [RFC6119]. These auxiliary Router-IDs MUST be
included in the link attribute described in Section 3.3.2. included in the link attribute described in Section 3.3.2.
It is desirable that the Router-ID assignments inside the Node It is desirable that the Router-ID assignments inside the Node
Descriptor are globally unique. However there may be Router-ID Descriptor are globally unique. However, there may be Router-ID
spaces (e.g. ISO) where no global registry exists, or worse, Router- spaces (e.g., ISO) where no global registry exists, or worse, Router-
IDs have been allocated following private-IP RFC 1918 [RFC1918] IDs have been allocated following the private-IP allocation described
allocation. BGP-LS uses the Autonomous System (AS) Number and BGP-LS in RFC 1918 [RFC1918]. BGP-LS uses the Autonomous System (AS) Number
Identifier (see Section 3.2.1.4) to disambiguate the Router-IDs, as and BGP-LS Identifier (see Section 3.2.1.4) to disambiguate the
described in Section 3.2.1.1. Router-IDs, as described in Section 3.2.1.1.
3.2.1.1. Globally Unique Node/Link/Prefix Identifiers 3.2.1.1. Globally Unique Node/Link/Prefix Identifiers
One problem that needs to be addressed is the ability to identify an One problem that needs to be addressed is the ability to identify an
IGP node globally (by "global", we mean within the BGP-LS database IGP node globally (by "globally", we mean within the BGP-LS database
collected by all BGP-LS speakers that talk to each other). This can collected by all BGP-LS speakers that talk to each other). This can
be expressed through the following two requirements: be expressed through the following two requirements:
(A) The same node MUST NOT be represented by two keys (otherwise one (A) The same node MUST NOT be represented by two keys (otherwise,
node will look like two nodes). one node will look like two nodes).
(B) Two different nodes MUST NOT be represented by the same key (B) Two different nodes MUST NOT be represented by the same key
(otherwise, two nodes will look like one node). (otherwise, two nodes will look like one node).
We define an "IGP domain" to be the set of nodes (hence, by extension We define an "IGP domain" to be the set of nodes (hence, by extension
links and prefixes), within which, each node has a unique IGP links and prefixes) within which each node has a unique IGP
representation by using the combination of Area-ID, Router-ID, representation by using the combination of Area-ID, Router-ID,
Protocol, Topology-ID, and Instance ID. The problem is that BGP may Protocol-ID, Multi-Topology ID, and Instance-ID. The problem is that
receive node/link/prefix information from multiple independent "IGP BGP may receive node/link/prefix information from multiple
domains" and we need to distinguish between them. Moreover, we can't independent "IGP domains", and we need to distinguish between them.
assume there is always one and only one IGP domain per AS. During Moreover, we can't assume there is always one and only one IGP domain
IGP transitions it may happen that two redundant IGPs are in place. per AS. During IGP transitions, it may happen that two redundant
IGPs are in place.
In Section 3.2.1.4 a set of sub-TLVs is described, which allows In Section 3.2.1.4, a set of sub-TLVs is described, which allows
specification of a flexible key for any given Node/Link information specification of a flexible key for any given node/link information
such that global uniqueness of the NLRI is ensured. such that global uniqueness of the NLRI is ensured.
3.2.1.2. Local Node Descriptors 3.2.1.2. Local Node Descriptors
The Local Node Descriptors TLV contains Node Descriptors for the node The Local Node Descriptors TLV contains Node Descriptors for the node
anchoring the local end of the link. This is a mandatory TLV in all anchoring the local end of the link. This is a mandatory TLV in all
three types of NLRIs (node, link, and prefix). The length of this three types of NLRIs (node, link, and prefix). The length of this
TLV is variable. The value contains one or more Node Descriptor Sub- TLV is variable. The value contains one or more Node Descriptor
TLVs defined in Section 3.2.1.4. Sub-TLVs defined in Section 3.2.1.4.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Node Descriptor Sub-TLVs (variable) // // Node Descriptor Sub-TLVs (variable) //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: Local Node Descriptors TLV format Figure 10: Local Node Descriptors TLV Format
3.2.1.3. Remote Node Descriptors 3.2.1.3. Remote Node Descriptors
The Remote Node Descriptors contains Node Descriptors for the node The Remote Node Descriptors TLV contains Node Descriptors for the
anchoring the remote end of the link. This is a mandatory TLV for node anchoring the remote end of the link. This is a mandatory TLV
link NLRIs. The length of this TLV is variable. The value contains for Link NLRIs. The length of this TLV is variable. The value
one or more Node Descriptor Sub-TLVs defined in Section 3.2.1.4. contains one or more Node Descriptor Sub-TLVs defined in
Section 3.2.1.4.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Node Descriptor Sub-TLVs (variable) // // Node Descriptor Sub-TLVs (variable) //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11: Remote Node Descriptors TLV format Figure 11: Remote Node Descriptors TLV Format
3.2.1.4. Node Descriptor Sub-TLVs 3.2.1.4. Node Descriptor Sub-TLVs
The Node Descriptor Sub-TLV type codepoints and lengths are listed in The Node Descriptor Sub-TLV type code points and lengths are listed
the following table: in the following table:
+--------------------+-------------------+----------+ +--------------------+-------------------+----------+
| Sub-TLV Code Point | Description | Length | | Sub-TLV Code Point | Description | Length |
+--------------------+-------------------+----------+ +--------------------+-------------------+----------+
| 512 | Autonomous System | 4 | | 512 | Autonomous System | 4 |
| 513 | BGP-LS Identifier | 4 | | 513 | BGP-LS Identifier | 4 |
| 514 | OSPF Area-ID | 4 | | 514 | OSPF Area-ID | 4 |
| 515 | IGP Router-ID | Variable | | 515 | IGP Router-ID | Variable |
+--------------------+-------------------+----------+ +--------------------+-------------------+----------+
Table 4: Node Descriptor Sub-TLVs Table 4: Node Descriptor Sub-TLVs
The sub-TLV values in Node Descriptor TLVs are defined as follows: The sub-TLV values in Node Descriptor TLVs are defined as follows:
Autonomous System: opaque value (32 Bit AS Number) Autonomous System: Opaque value (32-bit AS Number)
BGP-LS Identifier: opaque value (32 Bit ID). In conjunction with BGP-LS Identifier: Opaque value (32-bit ID). In conjunction with
ASN, uniquely identifies the BGP-LS domain. The combination of Autonomous System Number (ASN), uniquely identifies the BGP-LS
ASN and BGP-LS ID MUST be globally unique. All BGP-LS speakers domain. The combination of ASN and BGP-LS ID MUST be globally
within an IGP flooding-set (set of IGP nodes within which an LSP/ unique. All BGP-LS speakers within an IGP flooding-set (set of
LSA is flooded) MUST use the same ASN, BGP-LS ID tuple. If an IGP IGP nodes within which an LSP/LSA is flooded) MUST use the same
domain consists of multiple flooding-sets, then all BGP-LS ASN, BGP-LS ID tuple. If an IGP domain consists of multiple
speakers within the IGP domain SHOULD use the same ASN, BGP-LS ID flooding-sets, then all BGP-LS speakers within the IGP domain
tuple. The ASN, BGP Router-ID tuple (which is globally unique SHOULD use the same ASN, BGP-LS ID tuple.
[RFC6286] ) of one of the BGP-LS speakers within the flooding-set
(or IGP domain) may be used for all BGP-LS speakers in that
flooding-set (or IGP domain).
Area ID: It is used to identify the 32 Bit area to which the NLRI Area-ID: Used to identify the 32-bit area to which the NLRI belongs.
belongs. Area Identifier allows the different NLRIs of the same The Area Identifier allows different NLRIs of the same router to
router to be discriminated. be discriminated.
IGP Router ID: opaque value. This is a mandatory TLV. For an IS-IS IGP Router-ID: Opaque value. This is a mandatory TLV. For an IS-IS
non-Pseudonode, this contains 6 octet ISO node-ID (ISO system-ID). non-pseudonode, this contains a 6-octet ISO Node-ID (ISO system-
For an IS-IS Pseudonode corresponding to a LAN, this contains 6 ID). For an IS-IS pseudonode corresponding to a LAN, this
octet ISO node-ID of the "Designated Intermediate System" (DIS) contains the 6-octet ISO Node-ID of the Designated Intermediate
followed by one octet nonzero PSN identifier (7 octets in total). System (DIS) followed by a 1-octet, nonzero PSN identifier (7
For an OSPFv2 or OSPFv3 non-"Pseudonode", this contains the 4 octets in total). For an OSPFv2 or OSPFv3 non-pseudonode, this
octet Router-ID. For an OSPFv2 "Pseudonode" representing a LAN, contains the 4-octet Router-ID. For an OSPFv2 pseudonode
this contains the 4 octet Router-ID of the designated router (DR) representing a LAN, this contains the 4-octet Router-ID of the
followed by the 4 octet IPv4 address of the DR's interface to the Designated Router (DR) followed by the 4-octet IPv4 address of the
LAN (8 octets in total). Similarly, for an OSPFv3 "Pseudonode", DR's interface to the LAN (8 octets in total). Similarly, for an
this contains the 4 octet Router-ID of the DR followed by the 4 OSPFv3 pseudonode, this contains the 4-octet Router-ID of the DR
octet interface identifier of the DR's interface to the LAN (8 followed by the 4-octet interface identifier of the DR's interface
octets in total). The TLV size in combination with protocol to the LAN (8 octets in total). The TLV size in combination with
identifier enables the decoder to determine the type of the node. the protocol identifier enables the decoder to determine the type
of the node.
There can be at most one instance of each sub-TLV type present in There can be at most one instance of each sub-TLV type present in
any Node Descriptor. The sub-TLVs within a Node descriptor MUST any Node Descriptor. The sub-TLVs within a Node Descriptor MUST
be arranged in ascending order by sub-TLV type. This needs to be be arranged in ascending order by sub-TLV type. This needs to be
done in order to compare NLRIs, even when an implementation done in order to compare NLRIs, even when an implementation
encounters an unknown sub-TLV. Using stable sorting an encounters an unknown sub-TLV. Using stable sorting, an
implementation can do binary comparison of NLRIs and hence allow implementation can do binary comparison of NLRIs and hence allow
incremental deployment of new key sub-TLVs. incremental deployment of new key sub-TLVs.
3.2.1.5. Multi-Topology ID 3.2.1.5. Multi-Topology ID
The Multi-Topology ID (MT-ID) TLV carries one or more IS-IS or OSPF The Multi-Topology ID (MT-ID) TLV carries one or more IS-IS or OSPF
Multi-Topology IDs for a link, node or prefix. Multi-Topology IDs for a link, node, or prefix.
Semantics of the IS-IS MT-ID are defined in RFC5120, Section 7.2 Semantics of the IS-IS MT-ID are defined in Section 7.2 of RFC 5120
[RFC5120]. Semantics of the OSPF MT-ID are defined in RFC4915, [RFC5120]. Semantics of the OSPF MT-ID are defined in Section 3.7 of
Section 3.7 [RFC4915]. If the value in the MT-ID TLV is derived from RFC 4915 [RFC4915]. If the value in the MT-ID TLV is derived from
OSPF, then the upper 9 bits MUST be set to 0. Bits R are reserved, OSPF, then the upper 9 bits MUST be set to 0. Bits R are reserved
SHOULD be set to 0 when originated and ignored on receipt. and SHOULD be set to 0 when originated and ignored on receipt.
The format of the MT-ID TLV is shown in the following figure. The format of the MT-ID TLV is shown in the following figure.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length=2*n | | Type | Length=2*n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|R R R R| Multi-Topology ID 1 | .... // |R R R R| Multi-Topology ID 1 | .... //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// .... |R R R R| Multi-Topology ID n | // .... |R R R R| Multi-Topology ID n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 12: Multi-Topology ID TLV format Figure 12: Multi-Topology ID TLV Format
where Type is 263, Length is 2*n and n is the number of MT-IDs where Type is 263, Length is 2*n, and n is the number of MT-IDs
carried in the TLV. carried in the TLV.
The MT-ID TLV MAY be present in a Link Descriptor, a Prefix The MT-ID TLV MAY be present in a Link Descriptor, a Prefix
Descriptor, or in the BGP-LS attribute of a node NLRI. In a Link or Descriptor, or the BGP-LS attribute of a Node NLRI. In a Link or
Prefix Descriptor, only a single MT-ID TLV containing the MT-ID of Prefix Descriptor, only a single MT-ID TLV containing the MT-ID of
the topology where the link or the prefix is reachable is allowed. the topology where the link or the prefix is reachable is allowed.
In case one wants to advertise multiple topologies for a given Link In case one wants to advertise multiple topologies for a given Link
Descriptor or Prefix Descriptor, multiple NLRIs need to be generated Descriptor or Prefix Descriptor, multiple NLRIs need to be generated
where each NLRI contains an unique MT-ID. In the BGP-LS attribute of where each NLRI contains an unique MT-ID. In the BGP-LS attribute of
a node NLRI, one MT-ID TLV containing the array of MT-IDs of all a Node NLRI, one MT-ID TLV containing the array of MT-IDs of all
topologies where the node is reachable is allowed. topologies where the node is reachable is allowed.
3.2.2. Link Descriptors 3.2.2. Link Descriptors
The 'Link Descriptor' field is a set of Type/Length/Value (TLV) The Link Descriptor field is a set of Type/Length/Value (TLV)
triplets. The format of each TLV is shown in Section 3.1. The 'Link triplets. The format of each TLV is shown in Section 3.1. The Link
descriptor' TLVs uniquely identify a link among multiple parallel Descriptor TLVs uniquely identify a link among multiple parallel
links between a pair of anchor routers. A link described by the Link links between a pair of anchor routers. A link described by the Link
descriptor TLVs actually is a "half-link", a unidirectional Descriptor TLVs actually is a "half-link", a unidirectional
representation of a logical link. In order to fully describe a representation of a logical link. In order to fully describe a
single logical link, two originating routers advertise a half-link single logical link, two originating routers advertise a half-link
each, i.e., two link NLRIs are advertised for a given point-to-point each, i.e., two Link NLRIs are advertised for a given point-to-point
link. link.
The format and semantics of the 'value' fields in most 'Link The format and semantics of the Value fields in most Link Descriptor
Descriptor' TLVs correspond to the format and semantics of value TLVs correspond to the format and semantics of Value fields in IS-IS
fields in IS-IS Extended IS Reachability sub-TLVs, defined in Extended IS Reachability sub-TLVs, defined in [RFC5305], [RFC5307],
[RFC5305], [RFC5307] and [RFC6119]. Although the encodings for 'Link and [RFC6119]. Although the encodings for Link Descriptor TLVs were
Descriptor' TLVs were originally defined for IS-IS, the TLVs can originally defined for IS-IS, the TLVs can carry data sourced by
carry data sourced either by IS-IS or OSPF. either IS-IS or OSPF.
The following TLVs are valid as Link Descriptors in the Link NLRI: The following TLVs are valid as Link Descriptors in the Link NLRI:
+-----------+---------------------+---------------+-----------------+ +-----------+---------------------+--------------+------------------+
| TLV Code | Description | IS-IS TLV | Value defined | | TLV Code | Description | IS-IS TLV | Reference |
| Point | | /Sub-TLV | in: | | Point | | /Sub-TLV | (RFC/Section) |
+-----------+---------------------+---------------+-----------------+ +-----------+---------------------+--------------+------------------+
| 258 | Link Local/Remote | 22/4 | [RFC5307]/1.1 | | 258 | Link Local/Remote | 22/4 | [RFC5307]/1.1 |
| | Identifiers | | | | | Identifiers | | |
| 259 | IPv4 interface | 22/6 | [RFC5305]/3.2 | | 259 | IPv4 interface | 22/6 | [RFC5305]/3.2 |
| | address | | | | | address | | |
| 260 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 | | 260 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 |
| | address | | | | | address | | |
| 261 | IPv6 interface | 22/12 | [RFC6119]/4.2 | | 261 | IPv6 interface | 22/12 | [RFC6119]/4.2 |
| | address | | | | | address | | |
| 262 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 | | 262 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 |
| | address | | | | | address | | |
| 263 | Multi-Topology | --- | Section 3.2.1.5 | | 263 | Multi-Topology | --- | Section 3.2.1.5 |
| | Identifier | | | | | Identifier | | |
+-----------+---------------------+---------------+-----------------+ +-----------+---------------------+--------------+------------------+
Table 5: Link Descriptor TLVs Table 5: Link Descriptor TLVs
The information about a link present in the LSA/LSP originated by the The information about a link present in the LSA/LSP originated by the
local node of the link determines the set of TLVs in the Link local node of the link determines the set of TLVs in the Link
Descriptor of the link. Descriptor of the link.
If interface and neighbor addresses, either IPv4 or IPv6, are If interface and neighbor addresses, either IPv4 or IPv6, are
present, then the IP address TLVs are included in the link present, then the IP address TLVs are included in the Link
descriptor, but not the link local/remote Identifier TLV. The Descriptor but not the link local/remote Identifier TLV. The link
link local/remote identifiers MAY be included in the link local/remote identifiers MAY be included in the link attribute.
attribute.
If interface and neighbor addresses are not present and the link If interface and neighbor addresses are not present and the link
local/remote identifiers are present, then the link local/remote local/remote identifiers are present, then the link local/remote
Identifier TLV is included in the link descriptor. Identifier TLV is included in the Link Descriptor.
The Multi-Topology Identifier TLV is included in link descriptor The Multi-Topology Identifier TLV is included in Link Descriptor
if that information is present. if that information is present.
3.2.3. Prefix Descriptors 3.2.3. Prefix Descriptors
The 'Prefix Descriptor' field is a set of Type/Length/Value (TLV) The Prefix Descriptor field is a set of Type/Length/Value (TLV)
triplets. 'Prefix Descriptor' TLVs uniquely identify an IPv4 or IPv6 triplets. Prefix Descriptor TLVs uniquely identify an IPv4 or IPv6
Prefix originated by a Node. The following TLVs are valid as Prefix prefix originated by a node. The following TLVs are valid as Prefix
Descriptors in the IPv4/IPv6 Prefix NLRI: Descriptors in the IPv4/IPv6 Prefix NLRI:
+--------------+-----------------------+----------+-----------------+ +-------------+---------------------+----------+--------------------+
| TLV Code | Description | Length | Value defined | | TLV Code | Description | Length | Reference |
| Point | | | in: | | Point | | | (RFC/Section) |
+--------------+-----------------------+----------+-----------------+ +-------------+---------------------+----------+--------------------+
| 263 | Multi-Topology | variable | Section 3.2.1.5 | | 263 | Multi-Topology | variable | Section 3.2.1.5 |
| | Identifier | | | | | Identifier | | |
| 264 | OSPF Route Type | 1 | Section 3.2.3.1 | | 264 | OSPF Route Type | 1 | Section 3.2.3.1 |
| 265 | IP Reachability | variable | Section 3.2.3.2 | | 265 | IP Reachability | variable | Section 3.2.3.2 |
| | Information | | | | | Information | | |
+--------------+-----------------------+----------+-----------------+ +-------------+---------------------+----------+--------------------+
Table 6: Prefix Descriptor TLVs Table 6: Prefix Descriptor TLVs
3.2.3.1. OSPF Route Type 3.2.3.1. OSPF Route Type
OSPF Route Type is an optional TLV that MAY be present in Prefix The OSPF Route Type TLV is an optional TLV that MAY be present in
NLRIs. It is used to identify the OSPF route-type of the prefix. It Prefix NLRIs. It is used to identify the OSPF route type of the
is used when an OSPF prefix is advertised in the OSPF domain with prefix. It is used when an OSPF prefix is advertised in the OSPF
multiple route-types. The Route Type TLV allows the discrimination domain with multiple route types. The Route Type TLV allows the
of these advertisements. The format of the OSPF Route Type TLV is discrimination of these advertisements. The format of the OSPF Route
shown in the following figure. Type TLV is shown in the following figure.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Type | | Route Type |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Figure 13: OSPF Route Type TLV Format Figure 13: OSPF Route Type TLV Format
where the Type and Length fields of the TLV are defined in Table 6. where the Type and Length fields of the TLV are defined in Table 6.
The OSPF Route Type field values are defined in the OSPF protocol, The OSPF Route Type field values are defined in the OSPF protocol and
and can be one of the following: can be one of the following:
Intra-Area (0x1)
Inter-Area (0x2) o Intra-Area (0x1)
External 1 (0x3) o Inter-Area (0x2)
External 2 (0x4) o External 1 (0x3)
o External 2 (0x4)
NSSA 1 (0x5) o NSSA 1 (0x5)
NSSA 2 (0x6) o NSSA 2 (0x6)
3.2.3.2. IP Reachability Information 3.2.3.2. IP Reachability Information
The IP Reachability Information is a mandatory TLV that contains one The IP Reachability Information TLV is a mandatory TLV that contains
IP address prefix (IPv4 or IPv6) originally advertised in the IGP one IP address prefix (IPv4 or IPv6) originally advertised in the IGP
topology. Its purpose is to glue a particular BGP service NLRI by topology. Its purpose is to glue a particular BGP service NLRI by
virtue of its BGP next-hop to a given Node in the LSDB. A router virtue of its BGP next hop to a given node in the LSDB. A router
SHOULD advertise an IP Prefix NLRI for each of its BGP Next-hops. SHOULD advertise an IP Prefix NLRI for each of its BGP next hops.
The format of the IP Reachability Information TLV is shown in the The format of the IP Reachability Information TLV is shown in the
following figure: following figure:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length | IP Prefix (variable) // | Prefix Length | IP Prefix (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 14: IP Reachability Information TLV Format Figure 14: IP Reachability Information TLV Format
The Type and Length fields of the TLV are defined in Table 6. The The Type and Length fields of the TLV are defined in Table 6. The
following two fields determine the address-family reachability following two fields determine the reachability information of the
information. The 'Prefix Length' field contains the length of the address family. The Prefix Length field contains the length of the
prefix in bits. The 'IP Prefix' field contains the most significant prefix in bits. The IP Prefix field contains the most significant
octets of the prefix; i.e., 1 octet for prefix length 1 up to 8, 2 octets of the prefix, i.e., 1 octet for prefix length 1 up to 8, 2
octets for prefix length 9 to 16, 3 octets for prefix length 17 up to octets for prefix length 9 to 16, 3 octets for prefix length 17 up to
24 and 4 octets for prefix length 25 up to 32, etc. 24, 4 octets for prefix length 25 up to 32, etc.
3.3. The BGP-LS Attribute 3.3. The BGP-LS Attribute
This is an optional, non-transitive BGP attribute that is used to The BGP-LS attribute is an optional, non-transitive BGP attribute
carry link, node and prefix parameters and attributes. It is defined that is used to carry link, node, and prefix parameters and
as a set of Type/Length/Value (TLV) triplets, described in the attributes. It is defined as a set of Type/Length/Value (TLV)
following section. This attribute SHOULD only be included with Link- triplets, described in the following section. This attribute SHOULD
State NLRIs. This attribute MUST be ignored for all other address- only be included with Link-State NLRIs. This attribute MUST be
families. ignored for all other address families.
3.3.1. Node Attribute TLVs 3.3.1. Node Attribute TLVs
Node attribute TLVs are the TLVs that may be encoded in the BGP-LS Node attribute TLVs are the TLVs that may be encoded in the BGP-LS
attribute with a node NLRI. The following node attribute TLVs are attribute with a Node NLRI. The following Node Attribute TLVs are
defined: defined:
+--------------+-----------------------+----------+-----------------+ +-------------+----------------------+----------+-------------------+
| TLV Code | Description | Length | Value defined | | TLV Code | Description | Length | Reference |
| Point | | | in: | | Point | | | (RFC/Section) |
+--------------+-----------------------+----------+-----------------+ +-------------+----------------------+----------+-------------------+
| 263 | Multi-Topology | variable | Section 3.2.1.5 | | 263 | Multi-Topology | variable | Section 3.2.1.5 |
| | Identifier | | | | | Identifier | | |
| 1024 | Node Flag Bits | 1 | Section 3.3.1.1 | | 1024 | Node Flag Bits | 1 | Section 3.3.1.1 |
| 1025 | Opaque Node | variable | Section 3.3.1.5 | | 1025 | Opaque Node | variable | Section 3.3.1.5 |
| | Properties | | | | | Attribute | | |
| 1026 | Node Name | variable | Section 3.3.1.3 | | 1026 | Node Name | variable | Section 3.3.1.3 |
| 1027 | IS-IS Area Identifier | variable | Section 3.3.1.2 | | 1027 | IS-IS Area | variable | Section 3.3.1.2 |
| 1028 | IPv4 Router-ID of | 4 | [RFC5305]/4.3 | | | Identifier | | |
| | Local Node | | | | 1028 | IPv4 Router-ID of | 4 | [RFC5305]/4.3 |
| 1029 | IPv6 Router-ID of | 16 | [RFC6119]/4.1 | | | Local Node | | |
| | Local Node | | | | 1029 | IPv6 Router-ID of | 16 | [RFC6119]/4.1 |
+--------------+-----------------------+----------+-----------------+ | | Local Node | | |
+-------------+----------------------+----------+-------------------+
Table 7: Node Attribute TLVs Table 7: Node Attribute TLVs
3.3.1.1. Node Flag Bits TLV 3.3.1.1. Node Flag Bits TLV
The Node Flag Bits TLV carries a bit mask describing node attributes. The Node Flag Bits TLV carries a bit mask describing node attributes.
The value is a variable length bit array of flags, where each bit The value is a variable-length bit array of flags, where each bit
represents a node capability. represents a node capability.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|O|T|E|B|R|V| Rsvd| |O|T|E|B|R|V| Rsvd|
+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+
Figure 15: Node Flag Bits TLV format Figure 15: Node Flag Bits TLV Format
The bits are defined as follows: The bits are defined as follows:
+-----------------+-------------------------+-----------+ +-----------------+-------------------------+------------+
| Bit | Description | Reference | | Bit | Description | Reference |
+-----------------+-------------------------+-----------+ +-----------------+-------------------------+------------+
| 'O' | Overload Bit | [RFC1195] | | 'O' | Overload Bit | [ISO10589] |
| 'T' | Attached Bit | [RFC1195] | | 'T' | Attached Bit | [ISO10589] |
| 'E' | External Bit | [RFC2328] | | 'E' | External Bit | [RFC2328] |
| 'B' | ABR Bit | [RFC2328] | | 'B' | ABR Bit | [RFC2328] |
| 'R' | Router Bit | [RFC5340] | | 'R' | Router Bit | [RFC5340] |
| 'V' | V6 Bit | [RFC5340] | | 'V' | V6 Bit | [RFC5340] |
| Reserved (Rsvd) | Reserved for future use | | | Reserved (Rsvd) | Reserved for future use | |
+-----------------+-------------------------+-----------+ +-----------------+-------------------------+------------+
Table 8: Node Flag Bits Definitions Table 8: Node Flag Bits Definitions
3.3.1.2. IS-IS Area Identifier TLV 3.3.1.2. IS-IS Area Identifier TLV
An IS-IS node can be part of one or more IS-IS areas. Each of these An IS-IS node can be part of one or more IS-IS areas. Each of these
area addresses is carried in the IS-IS Area Identifier TLV. If area addresses is carried in the IS-IS Area Identifier TLV. If
multiple Area Addresses are present, multiple TLVs are used to encode multiple area addresses are present, multiple TLVs are used to encode
them. The IS-IS Area Identifier TLV may be present in the BGP-LS them. The IS-IS Area Identifier TLV may be present in the BGP-LS
attribute only when advertised in the Link-State Node NLRI. attribute only when advertised in the Link-State Node NLRI.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Area Identifier (variable) // // Area Identifier (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 16: IS-IS Area Identifier TLV Format Figure 16: IS-IS Area Identifier TLV Format
3.3.1.3. Node Name TLV 3.3.1.3. Node Name TLV
The Node Name TLV is optional. Its structure and encoding has been The Node Name TLV is optional. Its structure and encoding has been
borrowed from [RFC5301]. The value field identifies the symbolic borrowed from [RFC5301]. The Value field identifies the symbolic
name of the router node. This symbolic name can be the FQDN for the name of the router node. This symbolic name can be the Fully
router, it can be a subset of the FQDN (e.g. a hostname), or it can Qualified Domain Name (FQDN) for the router, it can be a subset of
be any string operators want to use for the router. The use of FQDN the FQDN (e.g., a hostname), or it can be any string operators want
or a subset of it is strongly RECOMMENDED. The maximum length of the to use for the router. The use of FQDN or a subset of it is strongly
'Node Name TLV' is 255 octets. RECOMMENDED. The maximum length of the Node Name TLV is 255 octets.
The Value field is encoded in 7-bit ASCII. If a user-interface for The Value field is encoded in 7-bit ASCII. If a user interface for
configuring or displaying this field permits Unicode characters, that configuring or displaying this field permits Unicode characters, that
user-interface is responsible for applying the ToASCII and/or user interface is responsible for applying the ToASCII and/or
ToUnicode algorithm as described in [RFC5890] to achieve the correct ToUnicode algorithm as described in [RFC5890] to achieve the correct
format for transmission or display. format for transmission or display.
Although [RFC5301] is an IS-IS specific extension, usage of the Node Although [RFC5301] describes an IS-IS-specific extension, usage of
Name TLV is possible for all protocols. How a router derives and the Node Name TLV is possible for all protocols. How a router
injects node names for e.g. OSPF nodes, is outside of the scope of derives and injects node names, e.g., OSPF nodes, is outside of the
this document. scope of this document.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Node Name (variable) // // Node Name (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 17: Node Name format Figure 17: Node Name Format
3.3.1.4. Local IPv4/IPv6 Router-ID 3.3.1.4. Local IPv4/IPv6 Router-ID TLVs
The local IPv4/IPv6 Router-ID TLVs are used to describe auxiliary The local IPv4/IPv6 Router-ID TLVs are used to describe auxiliary
Router-IDs that the IGP might be using, e.g., for TE and migration Router-IDs that the IGP might be using, e.g., for TE and migration
purposes like correlating a Node-ID between different protocols. If purposes such as correlating a Node-ID between different protocols.
there is more than one auxiliary Router-ID of a given type, then each If there is more than one auxiliary Router-ID of a given type, then
one is encoded in its own TLV. each one is encoded in its own TLV.
3.3.1.5. Opaque Node Attribute TLV 3.3.1.5. Opaque Node Attribute TLV
The Opaque Node Attribute TLV is an envelope that transparently The Opaque Node Attribute TLV is an envelope that transparently
carries optional node attribute TLVs advertised by a router. An carries optional Node Attribute TLVs advertised by a router. An
originating router shall use this TLV for encoding information originating router shall use this TLV for encoding information
specific to the protocol advertised in the NLRI header Protocol-ID specific to the protocol advertised in the NLRI header Protocol-ID
field or new protocol extensions to the protocol as advertised in the field or new protocol extensions to the protocol as advertised in the
NLRI header Protocol-ID field for which there is no protocol neutral NLRI header Protocol-ID field for which there is no protocol-neutral
representation in the BGP link-state NLRI. The primary use of the representation in the BGP Link-State NLRI. The primary use of the
Opaque Node Attribute TLV is to bridge the document lag between e.g. Opaque Node Attribute TLV is to bridge the document lag between,
a new IGP Link-state attribute being defined and the 'protocol- e.g., a new IGP link-state attribute being defined and the protocol-
neutral' BGP-LS extensions being published. A router for example neutral BGP-LS extensions being published. A router, for example,
could use this extension in order to advertise the native protocols could use this extension in order to advertise the native protocol's
node attribute TLVs, such as the OSPF Router Informational Node Attribute TLVs, such as the OSPF Router Informational
Capabilities TLV defined in [RFC4970], or the IGP TE Node Capability Capabilities TLV defined in [RFC7770] or the IGP TE Node Capability
Descriptor TLV described in [RFC5073]. Descriptor TLV described in [RFC5073].
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Opaque node attributes (variable) // // Opaque node attributes (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 18: Opaque Node attribute format Figure 18: Opaque Node Attribute Format
3.3.2. Link Attribute TLVs 3.3.2. Link Attribute TLVs
Link attribute TLVs are TLVs that may be encoded in the BGP-LS Link Attribute TLVs are TLVs that may be encoded in the BGP-LS
attribute with a link NLRI. Each 'Link Attribute' is a Type/Length/ attribute with a Link NLRI. Each 'Link Attribute' is a Type/Length/
Value (TLV) triplet formatted as defined in Section 3.1. The format Value (TLV) triplet formatted as defined in Section 3.1. The format
and semantics of the 'value' fields in some 'Link Attribute' TLVs and semantics of the Value fields in some Link Attribute TLVs
correspond to the format and semantics of value fields in IS-IS correspond to the format and semantics of the Value fields in IS-IS
Extended IS Reachability sub-TLVs, defined in [RFC5305] and Extended IS Reachability sub-TLVs, defined in [RFC5305] and
[RFC5307]. Other 'Link Attribute' TLVs are defined in this document. [RFC5307]. Other Link Attribute TLVs are defined in this document.
Although the encodings for 'Link Attribute' TLVs were originally Although the encodings for Link Attribute TLVs were originally
defined for IS-IS, the TLVs can carry data sourced either by IS-IS or defined for IS-IS, the TLVs can carry data sourced by either IS-IS or
OSPF. OSPF.
The following 'Link Attribute' TLVs are valid in the BGP-LS attribute The following Link Attribute TLVs are valid in the BGP-LS attribute
with a link NLRI: with a Link NLRI:
+-----------+---------------------+--------------+------------------+ +-----------+---------------------+--------------+------------------+
| TLV Code | Description | IS-IS TLV | Defined in: | | TLV Code | Description | IS-IS TLV | Reference |
| Point | | /Sub-TLV | | | Point | | /Sub-TLV | (RFC/Section) |
+-----------+---------------------+--------------+------------------+ +-----------+---------------------+--------------+------------------+
| 1028 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | | 1028 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 |
| | Local Node | | | | | Local Node | | |
| 1029 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | | 1029 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 |
| | Local Node | | | | | Local Node | | |
| 1030 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | | 1030 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 |
| | Remote Node | | | | | Remote Node | | |
| 1031 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | | 1031 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 |
| | Remote Node | | | | | Remote Node | | |
| 1088 | Administrative | 22/3 | [RFC5305]/3.1 | | 1088 | Administrative | 22/3 | [RFC5305]/3.1 |
| | group (color) | | | | | group (color) | | |
| 1089 | Maximum link | 22/9 | [RFC5305]/3.3 | | 1089 | Maximum link | 22/9 | [RFC5305]/3.4 |
| | bandwidth | | | | | bandwidth | | |
| 1090 | Max. reservable | 22/10 | [RFC5305]/3.5 | | 1090 | Max. reservable | 22/10 | [RFC5305]/3.5 |
| | link bandwidth | | | | | link bandwidth | | |
| 1091 | Unreserved | 22/11 | [RFC5305]/3.6 | | 1091 | Unreserved | 22/11 | [RFC5305]/3.6 |
| | bandwidth | | | | | bandwidth | | |
| 1092 | TE Default Metric | 22/18 | Section 3.3.2.3/ | | 1092 | TE Default Metric | 22/18 | Section 3.3.2.3 |
| 1093 | Link Protection | 22/20 | [RFC5307]/1.2 | | 1093 | Link Protection | 22/20 | [RFC5307]/1.2 |
| | Type | | | | | Type | | |
| 1094 | MPLS Protocol Mask | --- | Section 3.3.2.2 | | 1094 | MPLS Protocol Mask | --- | Section 3.3.2.2 |
| 1095 | IGP Metric | --- | Section 3.3.2.4 | | 1095 | IGP Metric | --- | Section 3.3.2.4 |
| 1096 | Shared Risk Link | --- | Section 3.3.2.5 | | 1096 | Shared Risk Link | --- | Section 3.3.2.5 |
| | Group | | | | | Group | | |
| 1097 | Opaque link | --- | Section 3.3.2.6 | | 1097 | Opaque Link | --- | Section 3.3.2.6 |
| | attribute | | | | | Attribute | | |
| 1098 | Link Name attribute | --- | Section 3.3.2.7 | | 1098 | Link Name | --- | Section 3.3.2.7 |
+-----------+---------------------+--------------+------------------+ +-----------+---------------------+--------------+------------------+
Table 9: Link Attribute TLVs Table 9: Link Attribute TLVs
3.3.2.1. IPv4/IPv6 Router-ID 3.3.2.1. IPv4/IPv6 Router-ID TLVs
The local/remote IPv4/IPv6 Router-ID TLVs are used to describe The local/remote IPv4/IPv6 Router-ID TLVs are used to describe
auxiliary Router-IDs that the IGP might be using, e.g., for TE auxiliary Router-IDs that the IGP might be using, e.g., for TE
purposes. All auxiliary Router-IDs of both the local and the remote purposes. All auxiliary Router-IDs of both the local and the remote
node MUST be included in the link attribute of each link NLRI. If node MUST be included in the link attribute of each Link NLRI. If
there are more than one auxiliary Router-ID of a given type, then there is more than one auxiliary Router-ID of a given type, then
multiple TLVs are used to encode them. multiple TLVs are used to encode them.
3.3.2.2. MPLS Protocol Mask TLV 3.3.2.2. MPLS Protocol Mask TLV
The MPLS Protocol Mask TLV carries a bit mask describing which MPLS The MPLS Protocol Mask TLV carries a bit mask describing which MPLS
signaling protocols are enabled. The length of this TLV is 1. The signaling protocols are enabled. The length of this TLV is 1. The
value is a bit array of 8 flags, where each bit represents an MPLS value is a bit array of 8 flags, where each bit represents an MPLS
Protocol capability. Protocol capability.
>Generation of the MPLS Protocol Mask TLV is only valid for and Generation of the MPLS Protocol Mask TLV is only valid for and SHOULD
SHOULD only be used with originators that have local link insight, only be used with originators that have local link insight, for
like for example the Protocol-IDs 'Static' or 'Direct' as per example, the Protocol-IDs 'Static configuration' or 'Direct' as per
Table 2. The 'MPLS Protocol Mask' TLV MUST NOT be included in NLRIs Table 2. The MPLS Protocol Mask TLV MUST NOT be included in NLRIs
with the other Protocol-IDs listed in Table 2. with the other Protocol-IDs listed in Table 2.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L|R| Reserved | |L|R| Reserved |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Figure 19: MPLS Protocol Mask TLV Figure 19: MPLS Protocol Mask TLV
The following bits are defined: The following bits are defined:
+------------+------------------------------------------+-----------+ +------------+------------------------------------------+-----------+
| Bit | Description | Reference | | Bit | Description | Reference |
+------------+------------------------------------------+-----------+ +------------+------------------------------------------+-----------+
| 'L' | Label Distribution Protocol (LDP) | [RFC5036] | | 'L' | Label Distribution Protocol (LDP) | [RFC5036] |
| 'R' | Extension to RSVP for LSP Tunnels (RSVP- | [RFC3209] | | 'R' | Extension to RSVP for LSP Tunnels | [RFC3209] |
| | TE) | | | | (RSVP-TE) | |
| 'Reserved' | Reserved for future use | | | 'Reserved' | Reserved for future use | |
+------------+------------------------------------------+-----------+ +------------+------------------------------------------+-----------+
Table 10: MPLS Protocol Mask TLV Codes Table 10: MPLS Protocol Mask TLV Codes
3.3.2.3. TE Default Metric TLV 3.3.2.3. TE Default Metric TLV
The TE Default Metric TLV carries the Traffic Engineering metric for The TE Default Metric TLV carries the Traffic Engineering metric for
this link. The length of this TLV is fixed at 4 octets. If a source this link. The length of this TLV is fixed at 4 octets. If a source
protocol uses a Metric width of less than 32 bits then the high order protocol uses a metric width of less than 32 bits, then the high-
bits of this field MUST be padded with zero. order bits of this field MUST be padded with zero.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE Default Link Metric | | TE Default Link Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 20: TE Default Metric TLV format Figure 20: TE Default Metric TLV Format
3.3.2.4. IGP Metric TLV 3.3.2.4. IGP Metric TLV
The IGP Metric TLV carries the metric for this link. The length of The IGP Metric TLV carries the metric for this link. The length of
this TLV is variable, depending on the metric width of the underlying this TLV is variable, depending on the metric width of the underlying
protocol. IS-IS small metrics have a length of 1 octet (the two most protocol. IS-IS small metrics have a length of 1 octet (the two most
significant bits are ignored). OSPF link metrics have a length of significant bits are ignored). OSPF link metrics have a length of 2
two octets. IS-IS wide-metrics have a length of three octets. octets. IS-IS wide metrics have a length of 3 octets.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// IGP Link Metric (variable length) // // IGP Link Metric (variable length) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 21: Metric TLV format Figure 21: IGP Metric TLV Format
3.3.2.5. Shared Risk Link Group TLV 3.3.2.5. Shared Risk Link Group TLV
The Shared Risk Link Group (SRLG) TLV carries the Shared Risk Link The Shared Risk Link Group (SRLG) TLV carries the Shared Risk Link
Group information (see Section 2.3, "Shared Risk Link Group Group information (see Section 2.3 ("Shared Risk Link Group
Information", of [RFC4202]). It contains a data structure consisting Information") of [RFC4202]). It contains a data structure consisting
of a (variable) list of SRLG values, where each element in the list of a (variable) list of SRLG values, where each element in the list
has 4 octets, as shown in Figure 22. The length of this TLV is 4 * has 4 octets, as shown in Figure 22. The length of this TLV is 4 *
(number of SRLG values). (number of SRLG values).
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Shared Risk Link Group Value | | Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// ............ // // ............ //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Shared Risk Link Group Value | | Shared Risk Link Group Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 22: Shared Risk Link Group TLV format Figure 22: Shared Risk Link Group TLV Format
The SRLG TLV for OSPF-TE is defined in [RFC4203]. In IS-IS the SRLG The SRLG TLV for OSPF-TE is defined in [RFC4203]. In IS-IS, the SRLG
information is carried in two different TLVs: the IPv4 (SRLG) TLV information is carried in two different TLVs: the IPv4 (SRLG) TLV
(Type 138) defined in [RFC5307], and the IPv6 SRLG TLV (Type 139) (Type 138) defined in [RFC5307] and the IPv6 SRLG TLV (Type 139)
defined in [RFC6119]. In Link-State NLRI both IPv4 and IPv6 SRLG defined in [RFC6119]. In Link-State NLRI, both IPv4 and IPv6 SRLG
information are carried in a single TLV. information are carried in a single TLV.
3.3.2.6. Opaque Link Attribute TLV 3.3.2.6. Opaque Link Attribute TLV
The Opaque link Attribute TLV is an envelope that transparently The Opaque Link Attribute TLV is an envelope that transparently
carries optional link attribute TLVs advertised by a router. An carries optional Link Attribute TLVs advertised by a router. An
originating router shall use this TLV for encoding information originating router shall use this TLV for encoding information
specific to the protocol advertised in the NLRI header Protocol-ID specific to the protocol advertised in the NLRI header Protocol-ID
field or new protocol extensions to the protocol as advertised in the field or new protocol extensions to the protocol as advertised in the
NLRI header Protocol-ID field for which there is no protocol neutral NLRI header Protocol-ID field for which there is no protocol-neutral
representation in the BGP link-state NLRI. The primary use of the representation in the BGP Link-State NLRI. The primary use of the
Opaque Link Attribute TLV is to bridge the document lag between e.g. Opaque Link Attribute TLV is to bridge the document lag between,
a new IGP Link-state attribute being defined and the 'protocol- e.g., a new IGP link-state attribute being defined and the 'protocol-
neutral' BGP-LS extensions being published. neutral' BGP-LS extensions being published.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Opaque link attributes (variable) // // Opaque link attributes (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 23: Opaque link attribute format Figure 23: Opaque Link Attribute TLV Format
3.3.2.7. Link Name TLV 3.3.2.7. Link Name TLV
The Link Name TLV is optional. The value field identifies the The Link Name TLV is optional. The Value field identifies the
symbolic name of the router link. This symbolic name can be the FQDN symbolic name of the router link. This symbolic name can be the FQDN
for the link, it can be a subset of the FQDN, or it can be any string for the link, it can be a subset of the FQDN, or it can be any string
operators want to use for the link. The use of FQDN or a subset of operators want to use for the link. The use of FQDN or a subset of
it is strongly RECOMMENDED. The maximum length of the 'Link Name it is strongly RECOMMENDED. The maximum length of the Link Name TLV
TLV' is 255 octets. is 255 octets.
The Value field is encoded in 7-bit ASCII. If a user-interface for The Value field is encoded in 7-bit ASCII. If a user interface for
configuring or displaying this field permits Unicode characters, that configuring or displaying this field permits Unicode characters, that
user-interface is responsible for applying the ToASCII and/or user interface is responsible for applying the ToASCII and/or
ToUnicode algorithm as described in [RFC5890] to achieve the correct ToUnicode algorithm as described in [RFC5890] to achieve the correct
format for transmission or display. format for transmission or display.
How a router derives and injects link names is outside of the scope How a router derives and injects link names is outside of the scope
of this document. of this document.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Link Name (variable) // // Link Name (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 24: Link Name format Figure 24: Link Name TLV Format
3.3.3. Prefix Attribute TLVs 3.3.3. Prefix Attribute TLVs
Prefixes are learned from the IGP topology (IS-IS or OSPF) with a set Prefixes are learned from the IGP topology (IS-IS or OSPF) with a set
of IGP attributes (such as metric, route tags, etc.) that MUST be of IGP attributes (such as metric, route tags, etc.) that MUST be
reflected into the BGP-LS attribute with a link NLRI. This section reflected into the BGP-LS attribute with a prefix NLRI. This section
describes the different attributes related to the IPv4/IPv6 prefixes. describes the different attributes related to the IPv4/IPv6 prefixes.
Prefix Attributes TLVs SHOULD be used when advertising NLRI types 3 Prefix Attribute TLVs SHOULD be used when advertising NLRI types 3
and 4 only. The following attributes TLVs are defined: and 4 only. The following Prefix Attribute TLVs are defined:
+---------------+----------------------+----------+-----------------+ +---------------+----------------------+----------+-----------------+
| TLV Code | Description | Length | Reference | | TLV Code | Description | Length | Reference |
| Point | | | | | Point | | | |
+---------------+----------------------+----------+-----------------+ +---------------+----------------------+----------+-----------------+
| 1152 | IGP Flags | 1 | Section 3.3.3.1 | | 1152 | IGP Flags | 1 | Section 3.3.3.1 |
| 1153 | Route Tag | 4*n | Section 3.3.3.2 | | 1153 | IGP Route Tag | 4*n | [RFC5130] |
| 1154 | Extended Tag | 8*n | Section 3.3.3.3 | | 1154 | IGP Extended Route | 8*n | [RFC5130] |
| 1155 | Prefix Metric | 4 | Section 3.3.3.4 | | | Tag | | |
| 1156 | OSPF Forwarding | 4 | Section 3.3.3.5 | | 1155 | Prefix Metric | 4 | [RFC5305] |
| 1156 | OSPF Forwarding | 4 | [RFC2328] |
| | Address | | | | | Address | | |
| 1157 | Opaque Prefix | variable | Section 3.3.3.6 | | 1157 | Opaque Prefix | variable | Section 3.3.3.6 |
| | Attribute | | | | | Attribute | | |
+---------------+----------------------+----------+-----------------+ +---------------+----------------------+----------+-----------------+
Table 11: Prefix Attribute TLVs Table 11: Prefix Attribute TLVs
3.3.3.1. IGP Flags TLV 3.3.3.1. IGP Flags TLV
IGP Flags TLV contains IS-IS and OSPF flags and bits originally The IGP Flags TLV contains IS-IS and OSPF flags and bits originally
assigned to the prefix. The IGP Flags TLV is encoded as follows: assigned to the prefix. The IGP Flags TLV is encoded as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|D|N|L|P| Resvd.| |D|N|L|P| Resvd.|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Figure 25: IGP Flag TLV format Figure 25: IGP Flag TLV Format
The value field contains bits defined according to the table below: The Value field contains bits defined according to the table below:
+----------+---------------------------+-----------+ +----------+---------------------------+-----------+
| Bit | Description | Reference | | Bit | Description | Reference |
+----------+---------------------------+-----------+ +----------+---------------------------+-----------+
| 'D' | IS-IS Up/Down Bit | [RFC5305] | | 'D' | IS-IS Up/Down Bit | [RFC5305] |
| 'N' | OSPF "no unicast" Bit | [RFC5340] | | 'N' | OSPF "no unicast" Bit | [RFC5340] |
| 'L' | OSPF "local address" Bit | [RFC5340] | | 'L' | OSPF "local address" Bit | [RFC5340] |
| 'P' | OSPF "propagate NSSA" Bit | [RFC5340] | | 'P' | OSPF "propagate NSSA" Bit | [RFC5340] |
| Reserved | Reserved for future use. | | | Reserved | Reserved for future use. | |
+----------+---------------------------+-----------+ +----------+---------------------------+-----------+
Table 12: IGP Flag Bits Definitions Table 12: IGP Flag Bits Definitions
3.3.3.2. Route Tag 3.3.3.2. IGP Route Tag TLV
Route Tag TLV carries original IGP TAGs (IS-IS [RFC5130] or OSPF) of The IGP Route Tag TLV carries original IGP Tags (IS-IS [RFC5130] or
the prefix and is encoded as follows: OSPF) of the prefix and is encoded as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Route Tags (one or more) // // Route Tags (one or more) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 26: IGP Route TAG TLV format Figure 26: IGP Route Tag TLV Format
Length is a multiple of 4. Length is a multiple of 4.
The value field contains one or more Route Tags as learned in the IGP The Value field contains one or more Route Tags as learned in the IGP
topology. topology.
3.3.3.3. Extended Route Tag 3.3.3.3. Extended IGP Route Tag TLV
Extended Route Tag TLV carries IS-IS Extended Route TAGs of the The Extended IGP Route Tag TLV carries IS-IS Extended Route Tags of
prefix [RFC5130] and is encoded as follows: the prefix [RFC5130] and is encoded as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Extended Route Tag (one or more) // // Extended Route Tag (one or more) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 27: Extended IGP Route TAG TLV format Figure 27: Extended IGP Route Tag TLV Format
Length is a multiple of 8. Length is a multiple of 8.
The 'Extended Route Tag' field contains one or more Extended Route The Extended Route Tag field contains one or more Extended Route Tags
Tags as learned in the IGP topology. as learned in the IGP topology.
3.3.3.4. Prefix Metric TLV 3.3.3.4. Prefix Metric TLV
Prefix Metric TLV is an optional attribute and may only appear once. The Prefix Metric TLV is an optional attribute and may only appear
If present, it carries the metric of the prefix as known in the IGP once. If present, it carries the metric of the prefix as known in
topology as described in Section 4 of [RFC5305] (and therefore the IGP topology as described in Section 4 of [RFC5305] (and
represents the reachability cost to the prefix). If not present, it therefore represents the reachability cost to the prefix). If not
means that the prefix is advertised without any reachability. present, it means that the prefix is advertised without any
reachability.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Metric | | Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 28: Prefix Metric TLV Format Figure 28: Prefix Metric TLV Format
Length is 4. Length is 4.
3.3.3.5. OSPF Forwarding Address TLV 3.3.3.5. OSPF Forwarding Address TLV
OSPF Forwarding Address TLV [RFC2328] and [RFC5340] carries the OSPF The OSPF Forwarding Address TLV [RFC2328] [RFC5340] carries the OSPF
forwarding address as known in the original OSPF advertisement. forwarding address as known in the original OSPF advertisement.
Forwarding address can be either IPv4 or IPv6. Forwarding address can be either IPv4 or IPv6.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Forwarding Address (variable) // // Forwarding Address (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 29: OSPF Forwarding Address TLV Format Figure 29: OSPF Forwarding Address TLV Format
Length is 4 for an IPv4 forwarding address an 16 for an IPv6 Length is 4 for an IPv4 forwarding address, and 16 for an IPv6
forwarding address. forwarding address.
3.3.3.6. Opaque Prefix Attribute TLV 3.3.3.6. Opaque Prefix Attribute TLV
The Opaque Prefix Attribute TLV is an envelope that transparently The Opaque Prefix Attribute TLV is an envelope that transparently
carries optional prefix attribute TLVs advertised by a router. An carries optional Prefix Attribute TLVs advertised by a router. An
originating router shall use this TLV for encoding information originating router shall use this TLV for encoding information
specific to the protocol advertised in the NLRI header Protocol-ID specific to the protocol advertised in the NLRI header Protocol-ID
field or new protocol extensions to the protocol as advertised in the field or new protocol extensions to the protocol as advertised in the
NLRI header Protocol-ID field for which there is no protocol neutral NLRI header Protocol-ID field for which there is no protocol-neutral
representation in the BGP link-state NLRI. The primary use of the representation in the BGP Link-State NLRI. The primary use of the
Opaque Prefix Attribute TLV is to bridge the document lag between Opaque Prefix Attribute TLV is to bridge the document lag between,
e.g. a new IGP Link-state attribute being defined and the 'protocol- e.g., a new IGP link-state attribute being defined and the protocol-
neutral' BGP-LS extensions being published. neutral BGP-LS extensions being published.
The format of the TLV is as follows: The format of the TLV is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Opaque Prefix Attributes (variable) // // Opaque Prefix Attributes (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 30: Opaque Prefix Attribute TLV Format Figure 30: Opaque Prefix Attribute TLV Format
Type is as specified in Table 11 and Length is variable. Type is as specified in Table 11. Length is variable.
3.4. BGP Next Hop Information 3.4. BGP Next-Hop Information
BGP link-state information for both IPv4 and IPv6 networks can be BGP link-state information for both IPv4 and IPv6 networks can be
carried over either an IPv4 BGP session, or an IPv6 BGP session. If carried over either an IPv4 BGP session or an IPv6 BGP session. If
an IPv4 BGP session is used, then the next hop in the MP_REACH_NLRI an IPv4 BGP session is used, then the next hop in the MP_REACH_NLRI
SHOULD be an IPv4 address. Similarly, if an IPv6 BGP session is SHOULD be an IPv4 address. Similarly, if an IPv6 BGP session is
used, then the next hop in the MP_REACH_NLRI SHOULD be an IPv6 used, then the next hop in the MP_REACH_NLRI SHOULD be an IPv6
address. Usually the next hop will be set to the local end-point address. Usually, the next hop will be set to the local endpoint
address of the BGP session. The next hop address MUST be encoded as address of the BGP session. The next-hop address MUST be encoded as
described in [RFC4760]. The length field of the next hop address described in [RFC4760]. The Length field of the next-hop address
will specify the next hop address-family. If the next hop length is will specify the next-hop address family. If the next-hop length is
4, then the next hop is an IPv4 address; if the next hop length is 4, then the next hop is an IPv4 address; if the next-hop length is
16, then it is a global IPv6 address and if the next hop length is 16, then it is a global IPv6 address; and if the next-hop length is
32, then there is one global IPv6 address followed by a link-local 32, then there is one global IPv6 address followed by a link-local
IPv6 address. The link-local IPv6 address should be used as IPv6 address. The link-local IPv6 address should be used as
described in [RFC2545]. For VPN SAFI, as per custom, an 8 byte described in [RFC2545]. For VPN Subsequent Address Family Identifier
route-distinguisher set to all zero is prepended to the next hop. (SAFI), as per custom, an 8-byte Route Distinguisher set to all zero
is prepended to the next hop.
The BGP Next Hop attribute is used by each BGP-LS speaker to validate The BGP Next Hop attribute is used by each BGP-LS speaker to validate
the NLRI it receives. In case identical NLRIs are sourced by the NLRI it receives. In case identical NLRIs are sourced by
multiple originators the BGP next hop attribute is used to tie-break multiple originators, the BGP Next Hop attribute is used to tiebreak
as per the standard BGP path decision process. This specification as per the standard BGP path decision process. This specification
doesn't mandate any rule regarding the re-write of the BGP Next Hop doesn't mandate any rule regarding the rewrite of the BGP Next Hop
attribute. attribute.
3.5. Inter-AS Links 3.5. Inter-AS Links
The main source of TE information is the IGP, which is not active on The main source of TE information is the IGP, which is not active on
inter-AS links. In some cases, the IGP may have information of inter-AS links. In some cases, the IGP may have information of
inter-AS links ([RFC5392], [RFC5316]). In other cases, an inter-AS links [RFC5392] [RFC5316]. In other cases, an
implementation SHOULD provide a means to inject inter-AS links into implementation SHOULD provide a means to inject inter-AS links into
BGP-LS. The exact mechanism used to provision the inter-AS links is BGP-LS. The exact mechanism used to provision the inter-AS links is
outside the scope of this document outside the scope of this document
3.6. Router-ID Anchoring Example: ISO Pseudonode 3.6. Router-ID Anchoring Example: ISO Pseudonode
Encoding of a broadcast LAN in IS-IS provides a good example of how Encoding of a broadcast LAN in IS-IS provides a good example of how
Router-IDs are encoded. Consider Figure 31. This represents a Router-IDs are encoded. Consider Figure 31. This represents a
Broadcast LAN between a pair of routers. The "real" (=non Broadcast LAN between a pair of routers. The "real" (non-pseudonode)
pseudonode) routers have both an IPv4 Router-ID and IS-IS Node-ID. routers have both an IPv4 Router-ID and IS-IS Node-ID. The
The pseudonode does not have an IPv4 Router-ID. Node1 is the DIS for pseudonode does not have an IPv4 Router-ID. Node1 is the DIS for the
the LAN. Two unidirectional links (Node1, Pseudonode 1) and LAN. Two unidirectional links (Node1, Pseudonode1) and (Pseudonode1,
(Pseudonode1, Node2) are being generated. Node2) are being generated.
The link NLRI of (Node1, Pseudonode1) is encoded as follows: the IGP The Link NLRI of (Node1, Pseudonode1) is encoded as follows. The IGP
Router-ID TLV of the local node descriptor is 6 octets long Router-ID TLV of the local Node Descriptor is 6 octets long and
containing ISO-ID of Node1, 1920.0000.2001; the IGP Router-ID TLV of contains the ISO-ID of Node1, 1920.0000.2001. The IGP Router-ID TLV
the remote node descriptor is 7 octets long containing the ISO-ID of of the remote Node Descriptor is 7 octets long and contains the ISO-
Pseudonode1, 1920.0000.2001.02. The BGP-LS attribute of this link ID of Pseudonode1, 1920.0000.2001.02. The BGP-LS attribute of this
contains one local IPv4 Router-ID TLV (TLV type 1028) containing link contains one local IPv4 Router-ID TLV (TLV type 1028) containing
192.0.2.1, the IPv4 Router-ID of Node1. 192.0.2.1, the IPv4 Router-ID of Node1.
The link NLRI of (Pseudonode1. Node2) is encoded as follows: the IGP The Link NLRI of (Pseudonode1, Node2) is encoded as follows. The IGP
Router-ID TLV of the local node descriptor is 7 octets long Router-ID TLV of the local Node Descriptor is 7 octets long and
containing the ISO-ID of Pseudonode1, 1920.0000.2001.02; the IGP contains the ISO-ID of Pseudonode1, 1920.0000.2001.02. The IGP
Router-ID TLV of the remote node descriptor is 6 octets long Router-ID TLV of the remote Node Descriptor is 6 octets long and
containing ISO-ID of Node2, 1920.0000.2002. The BGP-LS attribute of contains the ISO-ID of Node2, 1920.0000.2002. The BGP-LS attribute
this link contains one remote IPv4 Router-ID TLV (TLV type 1030) of this link contains one remote IPv4 Router-ID TLV (TLV type 1030)
containing 192.0.2.2, the IPv4 Router-ID of Node2. containing 192.0.2.2, the IPv4 Router-ID of Node2.
+-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+
| Node1 | | Pseudonode1 | | Node2 | | Node1 | | Pseudonode1 | | Node2 |
|1920.0000.2001.00|--->|1920.0000.2001.02|--->|1920.0000.2002.00| |1920.0000.2001.00|--->|1920.0000.2001.02|--->|1920.0000.2002.00|
| 192.0.2.1 | | | | 192.0.2.2 | | 192.0.2.1 | | | | 192.0.2.2 |
+-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+
Figure 31: IS-IS Pseudonodes Figure 31: IS-IS Pseudonodes
3.7. Router-ID Anchoring Example: OSPF Pseudonode 3.7. Router-ID Anchoring Example: OSPF Pseudonode
Encoding of a broadcast LAN in OSPF provides a good example of how Encoding of a broadcast LAN in OSPF provides a good example of how
Router-IDs and local Interface IPs are encoded. Consider Figure 32. Router-IDs and local Interface IPs are encoded. Consider Figure 32.
This represents a Broadcast LAN between a pair of routers. The This represents a Broadcast LAN between a pair of routers. The
"real" (=non pseudonode) routers have both an IPv4 Router-ID and an "real" (non-pseudonode) routers have both an IPv4 Router-ID and an
Area Identifier. The pseudonode does have an IPv4 Router-ID, an IPv4 Area Identifier. The pseudonode does have an IPv4 Router-ID, an IPv4
interface Address (for disambiguation) and an OSPF Area. Node1 is Interface Address (for disambiguation), and an OSPF Area. Node1 is
the DR for the LAN, hence its local IP address 10.1.1.1 is used both the DR for the LAN; hence, its local IP address 10.1.1.1 is used as
as the Router-ID and Interface IP for the Pseudonode keys. Two both the Router-ID and Interface IP for the pseudonode keys. Two
unidirectional links (Node1, Pseudonode 1) and (Pseudonode1, Node2) unidirectional links, (Node1, Pseudonode1) and (Pseudonode1, Node2),
are being generated. are being generated.
The link NLRI of (Node1, Pseudonode1) is encoded as follows: The Link NLRI of (Node1, Pseudonode1) is encoded as follows:
o Local Node Descriptor o Local Node Descriptor
TLV #515: IGP Router ID: 11.11.11.11 TLV #515: IGP Router-ID: 11.11.11.11
TLV #514: OSPF Area-ID: ID:0.0.0.0 TLV #514: OSPF Area-ID: ID:0.0.0.0
o Remote Node Descriptor o Remote Node Descriptor
TLV #515: IGP Router ID: 11.11.11.11:10.1.1.1 TLV #515: IGP Router-ID: 11.11.11.11:10.1.1.1
TLV #514: OSPF Area-ID: ID:0.0.0.0 TLV #514: OSPF Area-ID: ID:0.0.0.0
The link NLRI of (Pseudonode1, Node2) is encoded as follows: The Link NLRI of (Pseudonode1, Node2) is encoded as follows:
o Local Node Descriptor o Local Node Descriptor
TLV #515: IGP Router ID: 11.11.11.11:10.1.1.1 TLV #515: IGP Router-ID: 11.11.11.11:10.1.1.1
TLV #514: OSPF Area-ID: ID:0.0.0.0 TLV #514: OSPF Area-ID: ID:0.0.0.0
o Remote Node Descriptor o Remote Node Descriptor
TLV #515: IGP Router ID: 33.33.33.34
TLV #515: IGP Router-ID: 33.33.33.34
TLV #514: OSPF Area-ID: ID:0.0.0.0 TLV #514: OSPF Area-ID: ID:0.0.0.0
+-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+
| Node1 | | Pseudonode1 | | Node2 | | Node1 | | Pseudonode1 | | Node2 |
| 11.11.11.11 |--->| 11.11.11.11 |--->| 33.33.33.34 | | 11.11.11.11 |--->| 11.11.11.11 |--->| 33.33.33.34 |
| | | 10.1.1.1 | | | | | | 10.1.1.1 | | |
| Area 0 | | Area 0 | | Area 0 | | Area 0 | | Area 0 | | Area 0 |
+-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+ +-----------------+
Figure 32: OSPF Pseudonodes Figure 32: OSPF Pseudonodes
3.8. Router-ID Anchoring Example: OSPFv2 to IS-IS Migration 3.8. Router-ID Anchoring Example: OSPFv2 to IS-IS Migration
Graceful migration from one IGP to another requires coordinated Graceful migration from one IGP to another requires coordinated
operation of both protocols during the migration period. Such a operation of both protocols during the migration period. Such a
coordination requires identifying a given physical link in both IGPs. coordination requires identifying a given physical link in both IGPs.
The IPv4 Router-ID provides that "glue" which is present in the node The IPv4 Router-ID provides that "glue", which is present in the Node
descriptors of the OSPF link NLRI and in the link attribute of the Descriptors of the OSPF Link NLRI and in the link attribute of the
IS-IS link NLRI. IS-IS Link NLRI.
Consider a point-to-point link between two routers, A and B, that Consider a point-to-point link between two routers, A and B, that
initially were OSPFv2-only routers and then IS-IS is enabled on them. initially were OSPFv2-only routers and then IS-IS is enabled on them.
Node A has IPv4 Router-ID and ISO-ID; node B has IPv4 Router-ID, IPv6 Node A has IPv4 Router-ID and ISO-ID; node B has IPv4 Router-ID, IPv6
Router-ID and ISO-ID. Each protocol generates one link NLRI for the Router-ID, and ISO-ID. Each protocol generates one Link NLRI for the
link (A, B), both of which are carried by BGP-LS. The OSPFv2 link link (A, B), both of which are carried by BGP-LS. The OSPFv2 Link
NLRI for the link is encoded with the IPv4 Router-ID of nodes A and B NLRI for the link is encoded with the IPv4 Router-ID of nodes A and B
in the local and remote node descriptors, respectively. The IS-IS in the local and remote Node Descriptors, respectively. The IS-IS
link NLRI for the link is encoded with the ISO-ID of nodes A and B in Link NLRI for the link is encoded with the ISO-ID of nodes A and B in
the local and remote node descriptors, respectively. In addition, the local and remote Node Descriptors, respectively. In addition,
the BGP-LS attribute of the IS-IS link NLRI contains the TLV type the BGP-LS attribute of the IS-IS Link NLRI contains the TLV type
1028 containing the IPv4 Router-ID of node A; TLV type 1030 1028 containing the IPv4 Router-ID of node A, TLV type 1030
containing the IPv4 Router-ID of node B and TLV type 1031 containing containing the IPv4 Router-ID of node B, and TLV type 1031 containing
the IPv6 Router-ID of node B. In this case, by using IPv4 Router-ID, the IPv6 Router-ID of node B. In this case, by using IPv4 Router-ID,
the link (A, B) can be identified in both IS-IS and OSPF protocol. the link (A, B) can be identified in both the IS-IS and OSPF
protocol.
4. Link to Path Aggregation 4. Link to Path Aggregation
Distribution of all links available in the global Internet is Distribution of all links available in the global Internet is
certainly possible, however not desirable from a scaling and privacy certainly possible; however, it not desirable from a scaling and
point of view. Therefore an implementation may support link to path privacy point of view. Therefore, an implementation may support a
aggregation. Rather than advertising all specific links of a domain, link to path aggregation. Rather than advertising all specific links
an ASBR may advertise an "aggregate link" between a non-adjacent pair of a domain, an ASBR may advertise an "aggregate link" between a non-
of nodes. The "aggregate link" represents the aggregated set of link adjacent pair of nodes. The "aggregate link" represents the
properties between a pair of non-adjacent nodes. The actual methods aggregated set of link properties between a pair of non-adjacent
to compute the path properties (of bandwidth, metric) are outside the nodes. The actual methods to compute the path properties (of
scope of this document. The decision whether to advertise all bandwidth, metric, etc.) are outside the scope of this document. The
specific links or aggregated links is an operator's policy choice. decision whether to advertise all specific links or aggregated links
To highlight the varying levels of exposure, the following deployment is an operator's policy choice. To highlight the varying levels of
examples are discussed. exposure, the following deployment examples are discussed.
4.1. Example: No Link Aggregation 4.1. Example: No Link Aggregation
Consider Figure 33. Both AS1 and AS2 operators want to protect their Consider Figure 33. Both AS1 and AS2 operators want to protect their
inter-AS {R1,R3}, {R2, R4} links using RSVP-FRR LSPs. If R1 wants to inter-AS {R1, R3}, {R2, R4} links using RSVP-FRR LSPs. If R1 wants
compute its link-protection LSP to R3 it needs to "see" an alternate to compute its link-protection LSP to R3, it needs to "see" an
path to R3. Therefore the AS2 operator exposes its topology. All alternate path to R3. Therefore, the AS2 operator exposes its
BGP TE enabled routers in AS1 "see" the full topology of AS2 and topology. All BGP-TE-enabled routers in AS1 "see" the full topology
therefore can compute a backup path. Note that the decision if the of AS2 and therefore can compute a backup path. Note that the
direct link between {R3, R4} or the {R4, R5, R3) path is used is made computing router decides if the direct link between {R3, R4} or the
by the computing router. {R4, R5, R3} path is used.
AS1 : AS2 AS1 : AS2
: :
R1-------R3 R1-------R3
| : | \ | : | \
| : | R5 | : | R5
| : | / | : | /
R2-------R4 R2-------R4
: :
: :
Figure 33: No link aggregation Figure 33: No Link Aggregation
4.2. Example: ASBR to ASBR Path Aggregation 4.2. Example: ASBR to ASBR Path Aggregation
The brief difference between the "no-link aggregation" example and The brief difference between the "no-link aggregation" example and
this example is that no specific link gets exposed. Consider this example is that no specific link gets exposed. Consider
Figure 34. The only link which gets advertised by AS2 is an Figure 34. The only link that gets advertised by AS2 is an
"aggregate" link between R3 and R4. This is enough to tell AS1 that "aggregate" link between R3 and R4. This is enough to tell AS1 that
there is a backup path. However the actual links being used are there is a backup path. However, the actual links being used are
hidden from the topology. hidden from the topology.
AS1 : AS2 AS1 : AS2
: :
R1-------R3 R1-------R3
| : | | : |
| : | | : |
| : | | : |
R2-------R4 R2-------R4
: :
: :
Figure 34: ASBR link aggregation Figure 34: ASBR Link Aggregation
4.3. Example: Multi-AS Path Aggregation 4.3. Example: Multi-AS Path Aggregation
Service providers in control of multiple ASes may even decide to not Service providers in control of multiple ASes may even decide to not
expose their internal inter-AS links. Consider Figure 35. AS3 is expose their internal inter-AS links. Consider Figure 35. AS3 is
modeled as a single node which connects to the border routers of the modeled as a single node that connects to the border routers of the
aggregated domain. aggregated domain.
AS1 : AS2 : AS3 AS1 : AS2 : AS3
: : : :
R1-------R3----- R1-------R3-----
| : : \ | : : \
| : : vR0 | : : vR0
| : : / | : : /
R2-------R4----- R2-------R4-----
: : : :
: : : :
Figure 35: Multi-AS aggregation Figure 35: Multi-AS Aggregation
5. IANA Considerations 5. IANA Considerations
This document is the reference for Address Family Number 16388, 'BGP- IANA has assigned address family number 16388 (BGP-LS) in the
LS'. "Address Family Numbers" registry with this document as a reference.
This document requests code point 71 from the registry of Subsequent IANA has assigned SAFI values 71 (BGP-LS) and 72 (BGP-LS-VPN) in the
Address Family Numbers named 'BGP-LS'. "SAFI Values" sub-registry under the "Subsequent Address Family
Identifiers (SAFI) Parameters" registry.
This document requests a code point from the registry of Subsequent IANA has assigned value 29 (BGP-LS Attribute) in the "BGP Path
Address Family Numbers named 'BGP-LS-VPN'. The SAFI assignment does Attributes" sub-registry under the "Border Gateway Protocol (BGP)
not need to be out of the range 1-63 and may come out of the "First Parameters" registry.
Come First Served" range 128-240.
This document requests a code point from the BGP Path Attributes IANA has created a new "Border Gateway Protocol - Link State (BGP-LS)
registry. As per early allocation procedure this is Path Attribute Parameters" registry at <http://www.iana.org/assignments/bgp-ls-
29. parameters>. All of the following registries are BGP-LS specific and
are accessible under this registry:
All the following Registries are BGP-LS specific and shall be o "BGP-LS NLRI-Types" registry
accessible under the following URL: "http://www.iana.org/assignments/
bgp-ls-parameters" Title "Border Gateway Protocol - Link State (BGP-
LS) Parameters"
This document requests creation of a new registry for BGP-LS NLRI- Value 0 is reserved. The maximum value is 65535. The registry
Types. Value 0 is reserved. The maximum value is 65535. The has been populated with the values shown in Table 1. Allocations
registry will be initialized as shown in Table 1. Allocations within within the registry require documentation of the proposed use of
the registry will require documentation of the proposed use of the the allocated value (Specification Required) and approval by the
allocated value (=Specification required) and approval by the Designated Expert assigned by the IESG (see [RFC5226]).
Designated Expert assigned by the IESG (see [RFC5226]).
This document requests creation of a new registry for BGP-LS o "BGP-LS Protocol-IDs" registry
Protocol-IDs. Value 0 is reserved. The maximum value is 255. The
registry will be initialized as shown in Table 2. Allocations within
the registry will require documentation of the proposed use of the
allocated value (=Specification required) and approval by the
Designated Expert assigned by the IESG (see [RFC5226]).
This document requests creation of a new registry for BGP-LS Well- Value 0 is reserved. The maximum value is 255. The registry has
known Instance-IDs. The registry will be initialized as shown in been populated with the values shown in Table 2. Allocations
Table 3. Allocations within the registry will require documentation within the registry require documentation of the proposed use of
of the proposed use of the allocated value (=Specification required) the allocated value (Specification Required) and approval by the
and approval by the Designated Expert assigned by the IESG (see Designated Expert assigned by the IESG (see [RFC5226]).
[RFC5226]).
This document requests creation of a new registry for node anchor, o "BGP-LS Well-Known Instance-IDs" registry
link descriptor and link attribute TLVs. Values 0-255 are reserved.
Values 256-65535 will be used for code points. The registry will be The registry has been populated with the values shown in Table 3.
initialized as shown in Table 13. Allocations within the registry New allocations from the range 1-31 use the IANA allocation policy
will require documentation of the proposed use of the allocated value "Specification Required" and require approval by the Designated
(=Specification required) and approval by the Designated Expert Expert assigned by the IESG (see [RFC5226]). Values in the range
assigned by the IESG (see [RFC5226]). 32 to 2^64-1 are for "Private Use" and are not recorded by IANA.
o "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and
Attribute TLVs" registry
Values 0-255 are reserved. Values 256-65535 will be used for code
points. The registry has been populated with the values shown in
Table 13. Allocations within the registry require documentation
of the proposed use of the allocated value (Specification
Required) and approval by the Designated Expert assigned by the
IESG (see [RFC5226]).
5.1. Guidance for Designated Experts 5.1. Guidance for Designated Experts
In all cases of review by Designated Expert (DE) described here, the In all cases of review by the Designated Expert (DE) described here,
DE is expected to ascertain the existence of suitable documentation the DE is expected to ascertain the existence of suitable
(a specification) as described in [RFC5226], and to verify the documentation (a specification) as described in [RFC5226] and to
permanent and publically ready availability of the document. The DE verify that the document is permanently and publicly available. The
is also expected to check the clarity of purpose and use of the DE is also expected to check the clarity of purpose and use of the
requested code points. Lastly, the DE must verify that any requested code points. Last, the DE must verify that any
specification produced in the IETF that requests one of these code specification produced in the IETF that requests one of these code
points has been made available for review by the IDR working group, points has been made available for review by the IDR working group
and that any specification produced outside the IETF does not and that any specification produced outside the IETF does not
conflict with work that is active or already published within the conflict with work that is active or already published within the
IETF. IETF.
6. Manageability Considerations 6. Manageability Considerations
This section is structured as recommended in [RFC5706]. This section is structured as recommended in [RFC5706].
6.1. Operational Considerations 6.1. Operational Considerations
6.1.1. Operations 6.1.1. Operations
Existing BGP operational procedures apply. No new operation Existing BGP operational procedures apply. No new operation
procedures are defined in this document. It is noted that the NLRI procedures are defined in this document. It is noted that the NLRI
information present in this document purely carries application level information present in this document carries purely application-level
data that has no immediate corresponding forwarding state impact. As data that has no immediate corresponding forwarding state impact. As
such, any churn in reachability information has different impact than such, any churn in reachability information has a different impact
regular BGP updates which need to change forwarding state for an than regular BGP updates, which need to change the forwarding state
entire router. Furthermore it is anticipated that distribution of for an entire router. Furthermore, it is anticipated that
this NLRI will be handled by dedicated route-reflectors providing a distribution of this NLRI will be handled by dedicated route
level of isolation and fault-containment between different NLRI reflectors providing a level of isolation and fault containment
types. between different NLRI types.
6.1.2. Installation and Initial Setup 6.1.2. Installation and Initial Setup
Configuration parameters defined in Section 6.2.3 SHOULD be Configuration parameters defined in Section 6.2.3 SHOULD be
initialized to the following default values: initialized to the following default values:
o The Link-State NLRI capability is turned off for all neighbors. o The Link-State NLRI capability is turned off for all neighbors.
o The maximum rate at which Link-State NLRIs will be advertised/ o The maximum rate at which Link-State NLRIs will be advertised/
withdrawn from neighbors is set to 200 updates per second. withdrawn from neighbors is set to 200 updates per second.
6.1.3. Migration Path 6.1.3. Migration Path
The proposed extension is only activated between BGP peers after The proposed extension is only activated between BGP peers after
capability negotiation. Moreover, the extensions can be turned on/ capability negotiation. Moreover, the extensions can be turned on/
off an individual peer basis (see Section 6.2.3), so the extension off on an individual peer basis (see Section 6.2.3), so the extension
can be gradually rolled out in the network. can be gradually rolled out in the network.
6.1.4. Requirements on Other Protocols and Functional Components 6.1.4. Requirements on Other Protocols and Functional Components
The protocol extension defined in this document does not put new The protocol extension defined in this document does not put new
requirements on other protocols or functional components. requirements on other protocols or functional components.
6.1.5. Impact on Network Operation 6.1.5. Impact on Network Operation
Frequency of Link-State NLRI updates could interfere with regular BGP Frequency of Link-State NLRI updates could interfere with regular BGP
skipping to change at page 38, line 48 skipping to change at page 39, line 14
Distribution of Link-State NLRIs SHOULD be limited to a single admin Distribution of Link-State NLRIs SHOULD be limited to a single admin
domain, which can consist of multiple areas within an AS or multiple domain, which can consist of multiple areas within an AS or multiple
ASes. ASes.
6.1.6. Verifying Correct Operation 6.1.6. Verifying Correct Operation
Existing BGP procedures apply. In addition, an implementation SHOULD Existing BGP procedures apply. In addition, an implementation SHOULD
allow an operator to: allow an operator to:
o List neighbors with whom the Speaker is exchanging Link-State o List neighbors with whom the speaker is exchanging Link-State
NLRIs NLRIs.
6.2. Management Considerations 6.2. Management Considerations
6.2.1. Management Information 6.2.1. Management Information
The IDR working group has documented and continues to document parts The IDR working group has documented and continues to document parts
of the Management Information Base and YANG models for managing and of the Management Information Base and YANG models for managing and
monitoring BGP speakers and the sessions between them. It is monitoring BGP speakers and the sessions between them. It is
currently believed that the BGP session running BGP-LS is not currently believed that the BGP session running BGP-LS is not
substantially different from any other BGP session and can be managed substantially different from any other BGP session and can be managed
using the same data models. using the same data models.
6.2.2. Fault Management 6.2.2. Fault Management
If an implementation of BGP-LS detects a malformed attribute, then it If an implementation of BGP-LS detects a malformed attribute, then it
MUST use the 'Attribute Discard' action as per [RFC7606] Section 2. MUST use the 'Attribute Discard' action as per [RFC7606], Section 2.
An implementation of BGP-LS MUST perform the following syntactic An implementation of BGP-LS MUST perform the following syntactic
checks for determining if a message is malformed. checks for determining if a message is malformed.
o Does the sum of all TLVs found in the BGP LS attribute correspond o Does the sum of all TLVs found in the BGP-LS attribute correspond
to the BGP LS path attribute length? to the BGP-LS path attribute length?
o Does the sum of all TLVs found in the BGP MP_REACH_NLRI attribute o Does the sum of all TLVs found in the BGP MP_REACH_NLRI attribute
correspond to the BGP MP_REACH_NLRI length? correspond to the BGP MP_REACH_NLRI length?
o Does the sum of all TLVs found in the BGP MP_UNREACH_NLRI o Does the sum of all TLVs found in the BGP MP_UNREACH_NLRI
attribute correspond to the BGP MP_UNREACH_NLRI length? attribute correspond to the BGP MP_UNREACH_NLRI length?
o Does the sum of all TLVs found in a Node-, Link or Prefix o Does the sum of all TLVs found in a Node, Link or Prefix
Descriptor NLRI attribute correspond to the Node-, Link- or Prefix Descriptor NLRI attribute correspond to the Total NLRI Length
Descriptors 'Total NLRI Length' field? field of the Node, Link, or Prefix Descriptors?
o Does any fixed length TLV correspond to the TLV Length field in o Does any fixed-length TLV correspond to the TLV Length field in
this document? this document?
6.2.3. Configuration Management 6.2.3. Configuration Management
An implementation SHOULD allow the operator to specify neighbors to An implementation SHOULD allow the operator to specify neighbors to
which Link-State NLRIs will be advertised and from which Link-State which Link-State NLRIs will be advertised and from which Link-State
NLRIs will be accepted. NLRIs will be accepted.
An implementation SHOULD allow the operator to specify the maximum An implementation SHOULD allow the operator to specify the maximum
rate at which Link-State NLRIs will be advertised/withdrawn from rate at which Link-State NLRIs will be advertised/withdrawn from
neighbors. neighbors.
An implementation SHOULD allow the operator to specify the maximum An implementation SHOULD allow the operator to specify the maximum
number of Link-State NLRIs stored in router's RIB. number of Link-State NLRIs stored in a router's Routing Information
Base (RIB).
An implementation SHOULD allow the operator to create abstracted An implementation SHOULD allow the operator to create abstracted
topologies that are advertised to neighbors; Create different topologies that are advertised to neighbors and create different
abstractions for different neighbors. abstractions for different neighbors.
An implementation SHOULD allow the operator to configure a 64-bit An implementation SHOULD allow the operator to configure a 64-bit
instance ID. Instance-ID.
An implementation SHOULD allow the operator to configure a pair of An implementation SHOULD allow the operator to configure a pair of
ASN and BGP-LS identifier (Section 3.2.1.4) per flooding set in which ASN and BGP-LS identifiers (Section 3.2.1.4) per flooding set in
the node participates. which the node participates.
6.2.4. Accounting Management 6.2.4. Accounting Management
Not Applicable. Not Applicable.
6.2.5. Performance Management 6.2.5. Performance Management
An implementation SHOULD provide the following statistics: An implementation SHOULD provide the following statistics:
o Total number of Link-State NLRI updates sent/received o Total number of Link-State NLRI updates sent/received
o Number of Link-State NLRI updates sent/received, per neighbor o Number of Link-State NLRI updates sent/received, per neighbor
o Number of errored received Link-State NLRI updates, per neighbor o Number of errored received Link-State NLRI updates, per neighbor
o Total number of locally originated Link-State NLRIs o Total number of locally originated Link-State NLRIs
These statistics should be recorded as absolute counts since system These statistics should be recorded as absolute counts since system
or session start time. An implementation MAY also enhance this or session start time. An implementation MAY also enhance this
information by also recording peak per-second counts in each case. information by recording peak per-second counts in each case.
6.2.6. Security Management 6.2.6. Security Management
An operator SHOULD define an import policy to limit inbound updates An operator SHOULD define an import policy to limit inbound updates
as follows: as follows:
o Drop all updates from Consumer peers o Drop all updates from consumer peers.
An implementation MUST have means to limit inbound updates. An implementation MUST have the means to limit inbound updates.
7. TLV/Sub-TLV Code Points Summary 7. TLV/Sub-TLV Code Points Summary
This section contains the global table of all TLVs/Sub-TLVs defined This section contains the global table of all TLVs/sub-TLVs defined
in this document. in this document.
+-----------+---------------------+---------------+-----------------+ +-----------+---------------------+--------------+------------------+
| TLV Code | Description | IS-IS TLV/ | Value defined | | TLV Code | Description | IS-IS TLV/ | Reference |
| Point | | Sub-TLV | in: | | Point | | Sub-TLV | (RFC/Section) |
+-----------+---------------------+---------------+-----------------+ +-----------+---------------------+--------------+------------------+
| 256 | Local Node | --- | Section 3.2.1.2 | | 256 | Local Node | --- | Section 3.2.1.2 |
| | Descriptors | | | | | Descriptors | | |
| 257 | Remote Node | --- | Section 3.2.1.3 | | 257 | Remote Node | --- | Section 3.2.1.3 |
| | Descriptors | | | | | Descriptors | | |
| 258 | Link Local/Remote | 22/4 | [RFC5307]/1.1 | | 258 | Link Local/Remote | 22/4 | [RFC5307]/1.1 |
| | Identifiers | | | | | Identifiers | | |
| 259 | IPv4 interface | 22/6 | [RFC5305]/3.2 | | 259 | IPv4 interface | 22/6 | [RFC5305]/3.2 |
| | address | | | | | address | | |
| 260 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 | | 260 | IPv4 neighbor | 22/8 | [RFC5305]/3.3 |
| | address | | | | | address | | |
| 261 | IPv6 interface | 22/12 | [RFC6119]/4.2 | | 261 | IPv6 interface | 22/12 | [RFC6119]/4.2 |
| | address | | | | | address | | |
| 262 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 | | 262 | IPv6 neighbor | 22/13 | [RFC6119]/4.3 |
| | address | | | | | address | | |
| 263 | Multi-Topology ID | --- | Section 3.2.1.5 | | 263 | Multi-Topology ID | --- | Section 3.2.1.5 |
| 264 | OSPF Route Type | --- | Section 3.2.3 | | 264 | OSPF Route Type | --- | Section 3.2.3 |
| 265 | IP Reachability | --- | Section 3.2.3 | | 265 | IP Reachability | --- | Section 3.2.3 |
| | Information | | | | | Information | | |
| 512 | Autonomous System | --- | Section 3.2.1.4 | | 512 | Autonomous System | --- | Section 3.2.1.4 |
| 513 | BGP-LS Identifier | --- | Section 3.2.1.4 | | 513 | BGP-LS Identifier | --- | Section 3.2.1.4 |
| 514 | OSPF Area ID | --- | Section 3.2.1.4 | | 514 | OSPF Area-ID | --- | Section 3.2.1.4 |
| 515 | IGP Router-ID | --- | Section 3.2.1.4 | | 515 | IGP Router-ID | --- | Section 3.2.1.4 |
| 1024 | Node Flag Bits | --- | Section 3.3.1.1 | | 1024 | Node Flag Bits | --- | Section 3.3.1.1 |
| 1025 | Opaque Node | --- | Section 3.3.1.5 | | 1025 | Opaque Node | --- | Section 3.3.1.5 |
| | Properties | | | | | Attribute | | |
| 1026 | Node Name | variable | Section 3.3.1.3 | | 1026 | Node Name | variable | Section 3.3.1.3 |
| 1027 | IS-IS Area | variable | Section 3.3.1.2 | | 1027 | IS-IS Area | variable | Section 3.3.1.2 |
| | Identifier | | | | | Identifier | | |
| 1028 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | | 1028 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 |
| | Local Node | | | | | Local Node | | |
| 1029 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | | 1029 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 |
| | Local Node | | | | | Local Node | | |
| 1030 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 | | 1030 | IPv4 Router-ID of | 134/--- | [RFC5305]/4.3 |
| | Remote Node | | | | | Remote Node | | |
| 1031 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 | | 1031 | IPv6 Router-ID of | 140/--- | [RFC6119]/4.1 |
| | Remote Node | | | | | Remote Node | | |
| 1088 | Administrative | 22/3 | [RFC5305]/3.1 | | 1088 | Administrative | 22/3 | [RFC5305]/3.1 |
| | group (color) | | | | | group (color) | | |
| 1089 | Maximum link | 22/9 | [RFC5305]/3.3 | | 1089 | Maximum link | 22/9 | [RFC5305]/3.4 |
| | bandwidth | | | | | bandwidth | | |
| 1090 | Max. reservable | 22/10 | [RFC5305]/3.5 | | 1090 | Max. reservable | 22/10 | [RFC5305]/3.5 |
| | link bandwidth | | | | | link bandwidth | | |
| 1091 | Unreserved | 22/11 | [RFC5305]/3.6 | | 1091 | Unreserved | 22/11 | [RFC5305]/3.6 |
| | bandwidth | | | | | bandwidth | | |
| 1092 | TE Default Metric | 22/18 | Section 3.3.2.3 | | 1092 | TE Default Metric | 22/18 | Section 3.3.2.3 |
| 1093 | Link Protection | 22/20 | [RFC5307]/1.2 | | 1093 | Link Protection | 22/20 | [RFC5307]/1.2 |
| | Type | | | | | Type | | |
| 1094 | MPLS Protocol Mask | --- | Section 3.3.2.2 | | 1094 | MPLS Protocol Mask | --- | Section 3.3.2.2 |
| 1095 | IGP Metric | --- | Section 3.3.2.4 | | 1095 | IGP Metric | --- | Section 3.3.2.4 |
| 1096 | Shared Risk Link | --- | Section 3.3.2.5 | | 1096 | Shared Risk Link | --- | Section 3.3.2.5 |
| | Group | | | | | Group | | |
| 1097 | Opaque link | --- | Section 3.3.2.6 | | 1097 | Opaque Link | --- | Section 3.3.2.6 |
| | attribute | | | | | Attribute | | |
| 1098 | Link Name attribute | --- | Section 3.3.2.7 | | 1098 | Link Name | --- | Section 3.3.2.7 |
| 1152 | IGP Flags | --- | Section 3.3.3.1 | | 1152 | IGP Flags | --- | Section 3.3.3.1 |
| 1153 | Route Tag | --- | [RFC5130] | | 1153 | IGP Route Tag | --- | [RFC5130] |
| 1154 | Extended Tag | --- | [RFC5130] | | 1154 | IGP Extended Route | --- | [RFC5130] |
| 1155 | Prefix Metric | --- | [RFC5305] | | | Tag | | |
| 1156 | OSPF Forwarding | --- | [RFC2328] | | 1155 | Prefix Metric | --- | [RFC5305] |
| | Address | | | | 1156 | OSPF Forwarding | --- | [RFC2328] |
| 1157 | Opaque Prefix | --- | Section 3.3.3.6 | | | Address | | |
| | Attribute | | | | 1157 | Opaque Prefix | --- | Section 3.3.3.6 |
+-----------+---------------------+---------------+-----------------+ | | Attribute | | |
+-----------+---------------------+--------------+------------------+
Table 13: Summary Table of TLV/Sub-TLV code points Table 13: Summary Table of TLV/Sub-TLV Code Points
8. Security Considerations 8. Security Considerations
Procedures and protocol extensions defined in this document do not Procedures and protocol extensions defined in this document do not
affect the BGP security model. See the 'Security Considerations' affect the BGP security model. See the Security Considerations
section of [RFC4271] for a discussion of BGP security. Also refer to section of [RFC4271] for a discussion of BGP security. Also refer to
[RFC4272] and [RFC6952] for analysis of security issues for BGP. [RFC4272] and [RFC6952] for analysis of security issues for BGP.
In the context of the BGP peerings associated with this document, a In the context of the BGP peerings associated with this document, a
BGP Speaker MUST NOT accept updates from a Consumer peer. That is, a BGP speaker MUST NOT accept updates from a consumer peer. That is, a
participating BGP Speaker, should be aware of the nature of its participating BGP speaker should be aware of the nature of its
relationships for link state relationships and should protect itself relationships for link-state relationships and should protect itself
from peers sending updates that either represent erroneous from peers sending updates that either represent erroneous
information feedback loops, or are false input. Such protection can information feedback loops or are false input. Such protection can
be achieved by manual configuration of Consumer peers at the BGP be achieved by manual configuration of consumer peers at the BGP
Speaker. speaker.
An operator SHOULD employ a mechanism to protect a BGP Speaker An operator SHOULD employ a mechanism to protect a BGP speaker
against DDoS attacks from Consumers. The principal attack a consumer against DDoS attacks from consumers. The principal attack a consumer
may apply is to attempt to start multiple sessions either may apply is to attempt to start multiple sessions either
sequentially or simultaneously. Protection can be applied by sequentially or simultaneously. Protection can be applied by
imposing rate limits. imposing rate limits.
Additionally, it may be considered that the export of link state and Additionally, it may be considered that the export of link-state and
TE information as described in this document constitutes a risk to TE information as described in this document constitutes a risk to
confidentiality of mission-critical or commercially-sensitive confidentiality of mission-critical or commercially sensitive
information about the network. BGP peerings are not automatic and information about the network. BGP peerings are not automatic and
require configuration, thus it is the responsibility of the network require configuration; thus, it is the responsibility of the network
operator to ensure that only trusted Consumers are configured to operator to ensure that only trusted consumers are configured to
receive such information. receive such information.
9. Contributors 9. References
We would like to thank Robert Varga for the significant contribution
he gave to this document.
10. Acknowledgements
We would like to thank Nischal Sheth, Alia Atlas, David Ward, Derek
Yeung, Murtuza Lightwala, John Scudder, Kaliraj Vairavakkalai, Les
Ginsberg, Liem Nguyen, Manish Bhardwaj, Matt Miller, Mike Shand,
Peter Psenak, Rex Fernando, Richard Woundy, Steven Luong, Tamas
Mondal, Waqas Alam, Vipin Kumar, Naiming Shen, Carlos Pignataro,
Balaji Rajagopalan, Yakov Rekhter, Alvaro Retana, Barry Leiba, and
Ben Campbell for their comments.
11. References
11.1. Normative References 9.1. Normative References
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and [ISO10589] International Organization for Standardization,
dual environments", RFC 1195, DOI 10.17487/RFC1195, "Intermediate System to Intermediate System intra-domain
December 1990, <http://www.rfc-editor.org/info/rfc1195>. routeing information exchange protocol for use in
conjunction with the protocol for providing the
connectionless-mode network service (ISO 8473)", ISO/
IEC 10589, November 2002.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
DOI 10.17487/RFC2328, April 1998, DOI 10.17487/RFC2328, April 1998,
<http://www.rfc-editor.org/info/rfc2328>. <http://www.rfc-editor.org/info/rfc2328>.
skipping to change at page 45, line 23 skipping to change at page 45, line 27
[RFC5890] Klensin, J., "Internationalized Domain Names for [RFC5890] Klensin, J., "Internationalized Domain Names for
Applications (IDNA): Definitions and Document Framework", Applications (IDNA): Definitions and Document Framework",
RFC 5890, DOI 10.17487/RFC5890, August 2010, RFC 5890, DOI 10.17487/RFC5890, August 2010,
<http://www.rfc-editor.org/info/rfc5890>. <http://www.rfc-editor.org/info/rfc5890>.
[RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic [RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic
Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119, Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119,
February 2011, <http://www.rfc-editor.org/info/rfc6119>. February 2011, <http://www.rfc-editor.org/info/rfc6119>.
[RFC6286] Chen, E. and J. Yuan, "Autonomous-System-Wide Unique BGP
Identifier for BGP-4", RFC 6286, DOI 10.17487/RFC6286,
June 2011, <http://www.rfc-editor.org/info/rfc6286>.
[RFC6549] Lindem, A., Roy, A., and S. Mirtorabi, "OSPFv2 Multi- [RFC6549] Lindem, A., Roy, A., and S. Mirtorabi, "OSPFv2 Multi-
Instance Extensions", RFC 6549, DOI 10.17487/RFC6549, Instance Extensions", RFC 6549, DOI 10.17487/RFC6549,
March 2012, <http://www.rfc-editor.org/info/rfc6549>. March 2012, <http://www.rfc-editor.org/info/rfc6549>.
[RFC6822] Previdi, S., Ed., Ginsberg, L., Shand, M., Roy, A., and D. [RFC6822] Previdi, S., Ed., Ginsberg, L., Shand, M., Roy, A., and D.
Ward, "IS-IS Multi-Instance", RFC 6822, Ward, "IS-IS Multi-Instance", RFC 6822,
DOI 10.17487/RFC6822, December 2012, DOI 10.17487/RFC6822, December 2012,
<http://www.rfc-editor.org/info/rfc6822>. <http://www.rfc-editor.org/info/rfc6822>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K. [RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages", Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015, RFC 7606, DOI 10.17487/RFC7606, August 2015,
<http://www.rfc-editor.org/info/rfc7606>. <http://www.rfc-editor.org/info/rfc7606>.
11.2. Informative References 9.2. Informative References
[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G., [RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,
and E. Lear, "Address Allocation for Private Internets", and E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996, BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996,
<http://www.rfc-editor.org/info/rfc1918>. <http://www.rfc-editor.org/info/rfc1918>.
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006, RFC 4272, DOI 10.17487/RFC4272, January 2006,
<http://www.rfc-editor.org/info/rfc4272>. <http://www.rfc-editor.org/info/rfc4272>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <http://www.rfc-editor.org/info/rfc4364>. 2006, <http://www.rfc-editor.org/info/rfc4364>.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation [RFC4655] Farrel, A., Vasseur, JP., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006, DOI 10.17487/RFC4655, August 2006,
<http://www.rfc-editor.org/info/rfc4655>. <http://www.rfc-editor.org/info/rfc4655>.
[RFC4970] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and [RFC5073] Vasseur, JP., Ed. and JL. Le Roux, Ed., "IGP Routing
S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 4970, DOI 10.17487/RFC4970, July
2007, <http://www.rfc-editor.org/info/rfc4970>.
[RFC5073] Vasseur, J., Ed. and J. Le Roux, Ed., "IGP Routing
Protocol Extensions for Discovery of Traffic Engineering Protocol Extensions for Discovery of Traffic Engineering
Node Capabilities", RFC 5073, DOI 10.17487/RFC5073, Node Capabilities", RFC 5073, DOI 10.17487/RFC5073,
December 2007, <http://www.rfc-editor.org/info/rfc5073>. December 2007, <http://www.rfc-editor.org/info/rfc5073>.
[RFC5152] Vasseur, JP., Ed., Ayyangar, A., Ed., and R. Zhang, "A [RFC5152] Vasseur, JP., Ed., Ayyangar, A., Ed., and R. Zhang, "A
Per-Domain Path Computation Method for Establishing Inter- Per-Domain Path Computation Method for Establishing Inter-
Domain Traffic Engineering (TE) Label Switched Paths Domain Traffic Engineering (TE) Label Switched Paths
(LSPs)", RFC 5152, DOI 10.17487/RFC5152, February 2008, (LSPs)", RFC 5152, DOI 10.17487/RFC5152, February 2008,
<http://www.rfc-editor.org/info/rfc5152>. <http://www.rfc-editor.org/info/rfc5152>.
skipping to change at page 47, line 17 skipping to change at page 47, line 11
and Authentication for Routing Protocols (KARP) Design and Authentication for Routing Protocols (KARP) Design
Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
<http://www.rfc-editor.org/info/rfc6952>. <http://www.rfc-editor.org/info/rfc6952>.
[RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S., [RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
Previdi, S., Roome, W., Shalunov, S., and R. Woundy, Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
"Application-Layer Traffic Optimization (ALTO) Protocol", "Application-Layer Traffic Optimization (ALTO) Protocol",
RFC 7285, DOI 10.17487/RFC7285, September 2014, RFC 7285, DOI 10.17487/RFC7285, September 2014,
<http://www.rfc-editor.org/info/rfc7285>. <http://www.rfc-editor.org/info/rfc7285>.
[RFC7770] Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and
S. Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", RFC 7770, DOI 10.17487/RFC7770,
February 2016, <http://www.rfc-editor.org/info/rfc7770>.
Acknowledgements
We would like to thank Nischal Sheth, Alia Atlas, David Ward, Derek
Yeung, Murtuza Lightwala, John Scudder, Kaliraj Vairavakkalai, Les
Ginsberg, Liem Nguyen, Manish Bhardwaj, Matt Miller, Mike Shand,
Peter Psenak, Rex Fernando, Richard Woundy, Steven Luong, Tamas
Mondal, Waqas Alam, Vipin Kumar, Naiming Shen, Carlos Pignataro,
Balaji Rajagopalan, Yakov Rekhter, Alvaro Retana, Barry Leiba, and
Ben Campbell for their comments.
Contributors
We would like to thank Robert Varga for the significant contribution
he gave to this document.
Authors' Addresses Authors' Addresses
Hannes Gredler (editor) Hannes Gredler (editor)
Private Contributor Individual Contributor
Email: hannes@gredler.at Email: hannes@gredler.at
Jan Medved Jan Medved
Cisco Systems, Inc. Cisco Systems, Inc.
170, West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
US United States
Email: jmedved@cisco.com Email: jmedved@cisco.com
Stefano Previdi Stefano Previdi
Cisco Systems, Inc. Cisco Systems, Inc.
Via Del Serafico, 200 Via Del Serafico, 200
Rome 00142 Rome 00142
Italy Italy
Email: sprevidi@cisco.com Email: sprevidi@cisco.com
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