--- 1/draft-ietf-netmod-routing-cfg-03.txt 2012-07-09 11:14:14.157342298 +0200 +++ 2/draft-ietf-netmod-routing-cfg-04.txt 2012-07-09 11:14:14.249342757 +0200 @@ -1,46 +1,46 @@ NETMOD L. Lhotka Internet-Draft CZ.NIC -Intended status: Standards Track May 25, 2012 -Expires: November 26, 2012 +Intended status: Standards Track July 9, 2012 +Expires: January 10, 2013 A YANG Data Model for Routing Configuration - draft-ietf-netmod-routing-cfg-03 + draft-ietf-netmod-routing-cfg-04 Abstract This document contains a specification of three YANG modules. Together they form the core routing data model which serves as a framework for configuring a routing subsystem. It is therefore - expected that this module will be augmented by additional YANG + expected that these modules will be augmented by additional YANG modules defining data models for individual routing protocols and other related functions. The core routing data model provides common building blocks for such configurations - router instances, routes, routing tables, routing protocols and route filters. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on November 26, 2012. + This Internet-Draft will expire on January 10, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -77,23 +77,24 @@ 8. IPv6 Unicast Routing YANG Module . . . . . . . . . . . . . . . 38 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 47 10. Security Considerations . . . . . . . . . . . . . . . . . . . 49 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 50 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 51 12.1. Normative References . . . . . . . . . . . . . . . . . . . 51 12.2. Informative References . . . . . . . . . . . . . . . . . . 51 Appendix A. Example: Adding a New Routing Protocol . . . . . . . 52 Appendix B. Example: Reply to the NETCONF Message . . . . . 55 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 60 - C.1. Changes Between Versions -02 and -03 . . . . . . . . . . . 60 - C.2. Changes Between Versions -01 and -02 . . . . . . . . . . . 60 - C.3. Changes Between Versions -00 and -01 . . . . . . . . . . . 61 + C.1. Changes Between Versions -03 and -04 . . . . . . . . . . . 60 + C.2. Changes Between Versions -02 and -03 . . . . . . . . . . . 60 + C.3. Changes Between Versions -01 and -02 . . . . . . . . . . . 61 + C.4. Changes Between Versions -00 and -01 . . . . . . . . . . . 61 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 62 1. Introduction This document contains a specification of the following YANG modules: o Module "ietf-routing" provides generic components of a routing data model. o Module "ietf-ipv4-unicast-routing" augments the "ietf-routing" @@ -102,24 +103,24 @@ o Module "ietf-ipv6-unicast-routing" augments the "ietf-routing" module with additional data specific to IPv6 unicast, including the router configuration variables required by [RFC4861]. These modules together define the so-called core routing data model, which is proposed as a basis for the development of data models for more sophisticated routing configurations. While these three modules can be directly used for simple IP devices with static routing, their main purpose is to provide essential building blocks for more complicated setups involving multiple routing protocols, multicast - routing, additional address families, advanced functions such as - route filtering or policy routing etc. To this end, it is expected - that the core routing data model will be augmented by numerous - modules developed by other IETF working groups. + routing, additional address families, and advanced functions such as + route filtering or policy routing. To this end, it is expected that + the core routing data model will be augmented by numerous modules + developed by other IETF working groups. 2. Terminology and Notation 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 [RFC2119]. The following terms are defined in [RFC6241]: o client @@ -164,25 +165,25 @@ routing). core routing data model: YANG data model resulting from the combination of "ietf-routing", "ietf-ipv4-unicast-routing" and "ietf-ipv6-unicast-routing" modules. direct route: a route to a directly connected network. 2.2. Prefixes in Data Node Names - In this document, names of data nodes are used mostly without a - prefix, as long as it is clear from the context in which YANG module - each name is defined. Otherwise, names are prefixed using the - standard prefix associated with the corresponding YANG module, as - shown in Table 1. + In this document, names of data nodes, RPC methods and other data + model objects are used mostly without a prefix, as long as it is + clear from the context in which YANG module each name is defined. + Otherwise, names are prefixed using the standard prefix associated + with the corresponding YANG module, as shown in Table 1. +--------+---------------------------+--------------+ | Prefix | YANG module | Reference | +--------+---------------------------+--------------+ | ianaaf | iana-afn-safi | [IANA-IF-AF] | | | | | | if | ietf-interfaces | [YANG-IF] | | | | | | ip | ietf-ip | [YANG-IP] | | | | | @@ -274,47 +275,46 @@ | | +--rw name | | +--rw description? | | +--rw type | | +--rw connected-routing-tables | | | +--rw routing-table [name] | | | +--rw name | | | +--rw import-filter? | | | +--rw export-filter? | | +--rw static-routes | | +--rw v4ur:ipv4 - | | | +--rw v4ur:route [seqno] - | | | +--rw v4ur:seqno + | | | +--rw v4ur:route [id] + | | | +--rw v4ur:id | | | +--rw v4ur:description? | | | +--rw v4ur:outgoing-interface? | | | +--rw v4ur:dest-prefix | | | +--rw v4ur:next-hop? | | +--rw v6ur:ipv6 - | | +--rw v6ur:route [seqno] - | | +--rw v6ur:seqno + | | +--rw v6ur:route [id] + | | +--rw v6ur:id | | +--rw v6ur:description? | | +--rw v6ur:outgoing-interface? | | +--rw v6ur:dest-prefix | | +--rw v6ur:next-hop? | +--rw routing-tables | +--rw routing-table [name] | +--rw name | +--rw address-family? | +--rw safi? | +--rw description? | +--ro routes | | +--ro route + | | +--ro outgoing-interface? | | +--ro source-protocol | | +--ro age - | | +--ro v4ur:outgoing-interface? | | +--ro v4ur:dest-prefix? | | +--ro v4ur:next-hop? - | | +--ro v6ur:outgoing-interface? | | +--ro v6ur:dest-prefix? | | +--ro v6ur:next-hop? | +--rw recipient-routing-tables | +--rw recipient-routing-table [name] | +--rw name | +--rw filter? +--rw route-filters +--rw route-filter [name] +--rw name +--rw description? @@ -372,28 +372,28 @@ of route filters, denoted by "F" in Figure 2. 4.1. Router Each router instance in the core routing data model represents a logical router. The exact semantics of this term is left to implementations. For example, router instances may be completely isolated virtual routers or, alternatively, they may internally share certain information. - Network layer interfaces must be assigned to a router instance in - order to be able to participate in packet forwarding, routing - protocols and other operations of that router instance. The - assignment is accomplished by creating a corresponding entry in the - list of router interfaces ("rt:interface"). The key of the list + Each network layer interface must be assigned to one or more router + instances in order to be able to participate in packet forwarding, + routing protocols and other operations of those router instances. + The assignment is accomplished by creating a corresponding entry in + the list of router interfaces ("rt:interface"). The key of the list entry MUST be the name of a configured network layer interface, i.e., the value of a node /if:interfaces/if:interface/if:name defined in - the "ietf-interfaces" module.[YANG-IF]. + the "ietf-interfaces" module [YANG-IF]. Implementations MAY specify additional rules for the assignment of interfaces to logical routers. For example, it may be required that the sets of interfaces assigned to different logical routers be disjoint. Apart from the key, each entry of the "rt:interface" list MAY contain other configuration or operational state data related to the corresponding router interface. @@ -429,67 +429,79 @@ * on-link-flag, * preferred-lifetime, * autonomous-flag. The definitions and descriptions of the above parameters can be found in the text of the module "ietf-ipv6-unicast-routing" (Section 8). - NOTE: The "IsRouter" flag, which is also required by [RFC4861], is - implemented by the "ietf-ip" module [YANG-IP] (leaf "ip:ip- + NOTES: + + 1. The "IsRouter" flag, which is also required by [RFC4861], is + implemented in the "ietf-ip" module [YANG-IP] (leaf "ip:ip- forwarding"). + 2. The original specification [RFC4861] allows the implementations + to decide whether the "valid-lifetime" and "preferred-lifetime" + parameters remain the same in consecutive advertisements, or + decrement in real time. However, the latter behavior seems + problematic because the values might be reset again to the + (higher) configured values after a configuration is reloaded. + Moreover, no implementation is known to use the decrementing + behavior. The "ietf-ipv6-unicast-routing" module therefore + assumes the former behavior with constant values. + 4.2. Route Routes are basic units of information in a routing system. The core routing data model defines only the following minimal set of route attributes: o "destination-prefix": IP prefix specifying the set of destination addresses for which the route may be used. This attribute is mandatory. - o "next-hop": IP address of the adjacent router or host to which - packets with destination addresses belonging to destination-prefix - should be sent. + o "next-hop": IP address of an adjacent router or host to which + packets with destination addresses belonging to "destination- + prefix" should be sent. o "outgoing-interface": network interface that should be used for sending packets with destination addresses belonging to - destination-prefix. + "destination-prefix". - The above list of route attributes should suffice for a simple static + The above list of route attributes suffices for a simple static routing configuration. It is expected that future modules defining routing protocols will add other route attributes such as metrics or preferences. Routes and their attributes are used both in configuration data, for example as manually configured static routes, and in operational state data, for example as entries in routing tables. 4.3. Routing Tables Routing tables are lists of routes complemented with administrative data, namely: o "source-protocol": name of the routing protocol from which the route was originally obtained. o "age": number of seconds since the route was created or last updated. - Each routing table may only contain routes of the same address + Each routing table may contain only routes of the same address family. Address family information consists of two parameters - "address-family" and "safi" (Subsequent Address Family Identifier, SAFI). The permitted values for these two parameters are defined by - IANA and translated into YANG enumeration types "ianaaf:address- + IANA and represented using YANG enumeration types "ianaaf:address- family" and "ianaaf:subsequent-address-family" [IANA-IF-AF]. In the core routing data model, the "routing-table" node represents configuration while the descendant list of routes is defined as operational state data. The contents of route lists are controlled and manipulated by routing protocol operations which may result in route additions, removals and modifications. This also includes manipulations via the "static" and/or "direct" pseudo-protocols, see Section 4.4.1. @@ -587,21 +598,22 @@ A pseudo-protocol of the type "static" allows for specifying routes manually. It MAY be configured in zero or multiple instances, although a typical implementation will have exactly one instance per logical router. 4.4.2. Defining New Routing Protocols It is expected that future YANG modules will create data models for additional routing protocol types. Such a new module has to define the protocol-specific configuration and operational state data, and - fit it into the core routing framework in the following way : + it has to fit it into the core routing framework in the following + way: o A new identity MUST be defined for the routing protocol and its base identity MUST be set to "rt:routing-protocol", or to an identity derived from "rt:routing-protocol". o Additional route attributes MAY be defined, preferably in one place by means of defining a YANG grouping. The new attributes have to be inserted as operational state data by augmenting the definition of "rt:route" inside "rt:routing-table", and possibly to other places in the configuration, operational state data and @@ -684,22 +696,22 @@ } leaf metric { type rip-metric; default "1"; } } } Finally, global RIP configuration data are integrated into the "rt: routing-protocol" node by using the following "augment" statement, - which is valid only for routing protocol instances whose type is - "rip:rip": + which is again valid only for routing protocol instances whose type + is "rip:rip": augment "/rt:routing/rt:router/rt:routing-protocols/" + "rt:routing-protocol" { when "rt:type = 'rip:rip'"; container rip { leaf update-interval { type uint8 { range "10..60"; } units "seconds"; @@ -723,28 +735,30 @@ may be used by any or all router instances. By itself, the route filtering framework defined in this document allows for applying only the extreme routing policies which are represented by the following pre-defined route filter types: o "deny-all-route-filter": all routes are blocked, o "allow-all-route-filter": all routes are permitted. - It is expected that real route filtering frameworks will be developed - separately. + Note that the latter type is equivalent to no route filter. + + It is expected that more comprehensive route filtering frameworks + will be developed separately. Each route filter is identified by a name which MUST be unique within - a router instance. Its type MUST be specified by the "type" identity - reference - this opens the space for multiple route filtering - framework implementations. The default value for the route filter - type is the identity "deny-all-route-filter". + the entire configuration. Its type MUST be specified by the "type" + identity reference - this opens the space for multiple route + filtering framework implementations. The default value for the route + filter type is the identity "deny-all-route-filter". 4.6. RPC Operations The "ietf-routing" module defines two RPC operations: o active-route, o route-count. Their parameters and semantics are described in the following @@ -765,22 +779,22 @@ destination-address: Network layer destination address for which the active routes are requested. Positive Response: One or more "route" elements containing the active route(s). Negative Response: If the logical router is not found, the server sends an "rpc- - error" message with "error-tag" set to "missing-element", and - "error-app-tag" set to "router-not-found". + error" message with "error-tag" set to "data-missing", and "error- + app-tag" set to "router-not-found". If no route exists for the given destination address, the server sends an "rpc-error" message with "error-tag" set to "data- missing" and "error-app-tag" set to "no-route". 4.6.2. Operation "route-count" Description: Retrieve the total number of routes in a routing table. Parameters: @@ -788,26 +802,26 @@ router-name: Name of the logical router containing the routing table. routing-table: Name of the routing table. Positive Response: Element "number-of-routes" containing the requested nonnegative number. Negative Response: If the logical router or the routing table is not found, the server sends an "rpc-error" message with "error-tag" - set to "missing-element", and "error-app-tag" set to "router-not- + set to "data-missing", and "error-app-tag" set to "router-not- found" or "routing-table-not-found", respectively. 5. Interactions with Other YANG Modules - The semantics of the core routing data model also depends on several + The semantics of the core routing data model also depend on several configuration parameters that are defined in other YANG modules. The following subsections describe these interactions. 5.1. Module "ietf-interfaces" The following boolean switch is defined in the "ietf-interfaces" YANG module [YANG-IF]: /if:interfaces/if:interface/if:enabled @@ -851,21 +865,21 @@ destination prefix is set according to the configured IP address and subnet mask, and the interface is set as the outgoing interface for that route. 6. Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-routing@2012-05-24.yang" + file "ietf-routing@2012-07-09.yang" module ietf-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-routing"; prefix "rt"; import ietf-inet-types { prefix "inet"; } @@ -906,21 +920,21 @@ without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-05-24 { + revision 2012-07-09 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Identities */ identity routing-protocol { description @@ -949,23 +963,20 @@ identity deny-all-route-filter { base route-filter; description "Route filter that blocks all routes."; } identity allow-all-route-filter { base route-filter; description "Route filter that permits all routes. - - Note that use of this filter is equivalent to no filter at - all. "; } /* Type Definitions */ typedef router-ref { type leafref { path "/rt:routing/rt:router/rt:name"; } description @@ -1401,21 +1408,21 @@ } 7. IPv4 Unicast Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-ipv4-unicast-routing@2012-05-25.yang" + file "ietf-ipv4-unicast-routing@2012-07-09.yang" module ietf-ipv4-unicast-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"; prefix "v4ur"; import ietf-routing { prefix "rt"; } @@ -1457,21 +1464,21 @@ without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-05-24 { + revision 2012-07-09 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Groupings */ grouping route-content { description @@ -1521,35 +1528,40 @@ augment "/rt:routing/rt:router/rt:routing-protocols/" + "rt:routing-protocol/rt:static-routes" { description "This augment defines the configuration of the 'static' pseudo-protocol with data specific for IPv4 unicast."; container ipv4 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { - key "seqno"; + key "id"; ordered-by "user"; description "A user-ordered list of static routes."; - leaf seqno { + leaf id { type uint32 { range "1..max"; } description - "Sequential number of the route."; + 'Numeric identifier of the route. + + It is not required that the routes be sorted according + to their "id". + '; } leaf description { type string; description "Textual description of the route."; + } uses rt:route-content; uses route-content { refine "dest-prefix" { mandatory "true"; } } } } } @@ -1568,21 +1580,21 @@ } 8. IPv6 Unicast Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-ipv6-unicast-routing@2012-05-24.yang" + file "ietf-ipv6-unicast-routing@2012-07-09.yang" module ietf-ipv6-unicast-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing"; prefix "v6ur"; import ietf-routing { prefix "rt"; } @@ -1632,21 +1644,21 @@ without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-05-24 { + revision 2012-07-09 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Groupings */ grouping route-content { description @@ -1685,22 +1697,22 @@ "This augment is valid only for IPv6 unicast."; } description "Contents of the reply to 'rt:active-route' operation."; uses route-content; } /* Data nodes */ augment "/rt:routing/rt:router/rt:interfaces/rt:interface" { - when "/if:interfaces/if:interface[name=current()/name] " - + "/ip:ipv6/ip:enabled='true'" { + when "/if:interfaces/if:interface[name=current()/name]/ip:ipv6/" + + "ip:enabled='true'" { description "This augment is only valid for router interfaces with enabled IPv6. NOTE: Parameter 'is-router' is not included, it is expected that it will be implemented by the 'ietf-ip' module. "; } description "IPv6-specific parameters of router interfaces."; @@ -1865,59 +1877,44 @@ case advertise { leaf valid-lifetime { type uint32; units "seconds"; default "2592000"; description "The value to be placed in the Valid Lifetime in the Prefix Information option, in seconds. The designated value of all 1's (0xffffffff) represents infinity. - - Implementations may allow valid-lifetime to be - specified in two ways: - - 1. a time that decrements in real time, that is, - one that will result in a lifetime of zero at - the specified time in the future, - - 2. a fixed time that stays the same in consecutive - advertisements. "; } leaf on-link-flag { type boolean; default "true"; description "The value to be placed in the on-link flag ('L-bit') field in the Prefix Information option."; } leaf preferred-lifetime { type uint32; units "seconds"; + must ". <= ../valid-lifetime" { + description + "This value must not be larger than + valid-lifetime."; + } default "604800"; description "The value to be placed in the Preferred Lifetime in the Prefix Information option, in seconds. The designated value of all 1's (0xffffffff) represents infinity. - - Implementations MAY allow preferred-lifetime to be - specified in two ways: - - 1. a time that decrements in real time, that is, - one that will result in a lifetime of zero at a - specified time in the future, - - 2. a fixed time that stays the same in consecutive - advertisements. "; } leaf autonomous-flag { type boolean; default "true"; description "The value to be placed in the Autonomous Flag field in the Prefix Information option."; } } @@ -1930,30 +1928,34 @@ augment "/rt:routing/rt:router/rt:routing-protocols/" + "rt:routing-protocol/rt:static-routes" { description "This augment defines the configuration of the 'static' pseudo-protocol with data specific for IPv6 unicast."; container ipv6 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { - key "seqno"; + key "id"; ordered-by "user"; description "A user-ordered list of static routes."; - leaf seqno { + leaf id { type uint32 { range "1..max"; } description - "Sequential number of the route."; + 'Numeric identifier of the route. + + It is not required that the routes be sorted according + to their "id". + '; } leaf description { type string; description "Textual description of the route."; } uses rt:route-content; uses route-content { refine "dest-prefix" { mandatory "true"; @@ -2122,21 +2125,21 @@ Appendix A. Example: Adding a New Routing Protocol This appendix demonstrates how the core routing data model can be extended to support a new routing protocol. The YANG module "example-rip" shown below is intended only as an illustration rather than a real definition of a data model for the RIP routing protocol. For the sake of brevity, we do not follow all the guidelines specified in [RFC6087]. See also Section 4.4.2. - file "example-rip@2012-05-24.yang" + file "example-rip@2012-07-09.yang" module example-rip { namespace "http://example.com/rip"; prefix "rip"; import ietf-routing { prefix "rt"; } @@ -2259,22 +2262,22 @@ | | | Router A | | | +--------+--------+ eth1|198.51.100.1 |2001:db8:0:2::1 | Figure 3: Example network configuration - Router "A" then could send the following XML document as its reply to - the NETCONF message: + A reply to the NETCONF message sent by router "A" would then be + as follows: @@ -2348,28 +2351,28 @@ st0 Static routing is used for the internal network. rt:static - 1 + 1 0.0.0.0/0 192.0.2.2 - 1 + 1 ::/0 2001:db8:0:1::2 main-ipv4-unicast @@ -2430,21 +2433,35 @@ Appendix C. Change Log RFC Editor: remove this section upon publication as an RFC. -C.1. Changes Between Versions -02 and -03 +C.1. Changes Between Versions -03 and -04 + + o Changed "error-tag" for both RPC methods from "missing element" to + "data-missing". + + o Removed the decrementing behavior for advertised IPv6 prefix + parameters "valid-lifetime" and "preferred-lifetime". + + o Changed the key of the static route lists from "seqno" to "id" + because the routes needn't be sorted. + + o Added 'must' constraint saying that "preferred-lifetime" must not + be greater than "valid-lifetime". + +C.2. Changes Between Versions -02 and -03 o Module "iana-afn-safi" moved to I-D "iana-if-type". o Removed forwarding table. o RPC "get-route" changed to "active-route". Its output is a list of routes (for multi-path routing). o New RPC "route-count". @@ -2462,21 +2479,21 @@ "ietf-ip". o Added "router-id" leaf. o Specified the names for IPv4/IPv6 unicast main routing tables. o Route parameter "last-modified" changed to "age". o Added container "recipient-routing-tables". -C.2. Changes Between Versions -01 and -02 +C.3. Changes Between Versions -01 and -02 o Added module "ietf-ipv6-unicast-routing". o The example in Appendix B now uses IP addresses from blocks reserved for documentation. o Direct routes appear by default in the FIB table. o Network layer interfaces must be assigned to a router instance. Additional interface configuration may be present. @@ -2486,21 +2503,21 @@ o Additional "must" statements were added. o The "route-content" grouping for IPv4 and IPv6 unicast now includes the material from the "ietf-routing" version via "uses rt:route-content". o Explanation of symbols in the tree representation of data model hierarchy. -C.3. Changes Between Versions -00 and -01 +C.4. Changes Between Versions -00 and -01 o AFN/SAFI-independent stuff was moved to the "ietf-routing" module. o Typedefs for AFN and SAFI were placed in a separate "iana-afn- safi" module. o Names of some data nodes were changed, in particular "routing- process" is now "router". o The restriction of a single AFN/SAFI per router was lifted.