--- 1/draft-ietf-idr-bgp-prefix-sid-26.txt 2018-06-26 13:13:14.696878385 -0700 +++ 2/draft-ietf-idr-bgp-prefix-sid-27.txt 2018-06-26 13:13:14.736879357 -0700 @@ -1,23 +1,23 @@ IDR S. Previdi Internet-Draft C. Filsfils Intended status: Standards Track A. Lindem, Ed. -Expires: December 23, 2018 Cisco Systems +Expires: December 28, 2018 Cisco Systems A. Sreekantiah H. Gredler RtBrick Inc. - June 21, 2018 + June 26, 2018 Segment Routing Prefix SID extensions for BGP - draft-ietf-idr-bgp-prefix-sid-26 + draft-ietf-idr-bgp-prefix-sid-27 Abstract Segment Routing (SR) leverages the source routing paradigm. A node steers a packet through an ordered list of instructions, called segments. A segment can represent any instruction, topological or service-based. The ingress node prepends an SR header to a packet containing a set of segment identifiers (SID). Each SID represents a topological or a service-based instruction. Per-flow state is maintained only on the ingress node of the SR domain. An SR domain @@ -44,21 +44,21 @@ 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 December 23, 2018. + This Internet-Draft will expire on December 28, 2018. Copyright Notice Copyright (c) 2018 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 @@ -70,32 +70,32 @@ Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. MPLS BGP Prefix SID . . . . . . . . . . . . . . . . . . . . . 4 3. BGP Prefix-SID Attribute . . . . . . . . . . . . . . . . . . 5 3.1. Label-Index TLV . . . . . . . . . . . . . . . . . . . . . 5 3.2. Originator SRGB TLV . . . . . . . . . . . . . . . . . . . 6 4. Receiving BGP Prefix-SID Attribute . . . . . . . . . . . . . 8 4.1. MPLS Dataplane: Labeled Unicast . . . . . . . . . . . . . 8 - 5. Advertising BGP Prefix-SID Attribute . . . . . . . . . . . . 9 + 5. Advertising BGP Prefix-SID Attribute . . . . . . . . . . . . 10 5.1. MPLS Dataplane: Labeled Unicast . . . . . . . . . . . . . 10 6. Error Handling of BGP Prefix-SID Attribute . . . . . . . . . 10 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 8. Manageability Considerations . . . . . . . . . . . . . . . . 12 9. Security Considerations . . . . . . . . . . . . . . . . . . . 13 - 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 13 + 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 12.1. Normative References . . . . . . . . . . . . . . . . . . 14 - 12.2. Informative References . . . . . . . . . . . . . . . . . 15 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 + 12.2. Informative References . . . . . . . . . . . . . . . . . 16 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction The Segment Routing (SR) architecture leverages the source routing paradigm. A segment represents either a topological instruction such as "go to prefix P following shortest path" or a service instruction. Other types of segments may be defined in the future. A segment is identified through a Segment Identifier (SID). An SR domain is defined as a single administrative domain for global SID @@ -318,20 +318,26 @@ build their neighbor's Segment Routing Global Block (SRGB) are included in [I-D.ietf-spring-segment-routing-mpls]). The Originator SRGB TLV may only appear in a BGP Prefix-SID attribute attached to IPv4/IPv6 Labeled Unicast prefixes ([RFC8277]). It MUST be ignored when received for other BGP AFI/SAFI combinations. Since the Label-Index TLV is required for IPv4/IPv6 prefix applicability, the Originator SRGB TLV will be ignored if it is not specified consistent with Section 6. + If a BGP speaker receives a node's SRGB as an attribute of the BGP-LS + Node NLRI and the BGP speaker also receives the same node's SRGB in a + BGP Prefix-SID attribute, then the received values should be the + same. If the values are different, the values advertised in the BGP- + LS NLRI SHOULD be preferred and an error should be logged. + 4. Receiving BGP Prefix-SID Attribute A BGP speaker receiving a BGP Prefix-SID attribute from an External BGP (EBGP) neighbor residing outside the boundaries of the SR domain MUST discard the attribute unless it is configured to accept the attribute from the EBGP neighbor. A BGP speaker SHOULD log an error for further analysis when discarding an attribute. 4.1. MPLS Dataplane: Labeled Unicast @@ -582,20 +586,25 @@ boundary of the SR/administrative domain. Local BGP attribute filtering policies and mechanisms are not standardized and, consequently, beyond the scope of this document. To prevent a Denial-of-Service (DoS) or Distributed-Denial-of-Service (DDoS) attack due to excessive BGP updates with an invalid or conflicting BGP Prefix-SID attribute, error log message rate-limiting as well as suppression of duplicate error log messages SHOULD be deployed. + Since BGP-LS is the preferred method for advertising SRGB + information, the BGP speaker SHOULD log an error if a BGP Prefix-SID + attribute is received with SRGB information different from that + received as an attribute of the same node's BGP-LS Node NLRI. + 10. Contributors Keyur Patel Arrcus, Inc. US Email: Keyur@arrcus.com Saikat Ray Unaffiliated