Network Working Group J. Dong Internet-Draft Huawei Technologies Intended status: Standards Track October 19, 2015 Expires: April 21, 2016 Enhanced End-of-RIB Marker for BGP draft-dong-idr-enhanced-end-of-rib-00 Abstract This document specifies an enhanced BGP End-of-RIB marker which can facilitate fine granular BGP route convergence for various BGP based network services. A new BGP capability to negotiate the usage of the enhanced End-of-RIB marker is also specified. 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]. 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 April 21, 2016. Copyright Notice Copyright (c) 2015 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 Dong Expires April 21, 2016 [Page 1] Internet-Draft Enhanced BGP End-of-RIB Marker October 2015 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Enhanced End-of-RIB Marker . . . . . . . . . . . . . . . . . 3 3. BGP Enhanced End-of-RIB Capability . . . . . . . . . . . . . 3 4. Usage of Enhanced End-of-RIB Marker . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 8.1. Normative References . . . . . . . . . . . . . . . . . . 4 8.2. Informative References . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction BGP [RFC4271] has been extended for the advertisement of different kinds of information for various network services, some of which may involve the exchange and synchronization of hundreds of thousands of BGP routes. The time of BGP convergence can impact the availability of some critical services, or the service of some high priority customers. For example, for Layer-3 Virtual Private Network (L3VPN) [RFC4364] service, there can be more than thousands of VPN customers. Ideally the route convergence of VPN customers should be independent of each other. However, with existing BGP mechanism, the convergence of all the customers' VPN routes is treated as a whole, which is not optimal and may slow down the route convergence of particular VPN customers. BGP Graceful Restart (GR) [RFC4724] defines an End-of-RIB marker which can be used to indicate to BGP peers the completion of route update for specific address family. Such End-of-RIB marker is sent to BGP peers only when all the routes of specific address family has been advertised. Before this End-of-RIB is received from BGP peers, there is no way to know whether the update for a particular VPN customer has completed, consequently this would delay the route selection and further processing for that customer. In other word, BGP route selection for any VPN customer has to be suspended until the End-of-RIB marker for the corresponding address family is received from BGP peers. Dong Expires April 21, 2016 [Page 2] Internet-Draft Enhanced BGP End-of-RIB Marker October 2015 Besides, update of the RT membership information with BGP RT- Constrain mechanism [RFC4684] may trigger the advertisement of a set of BGP routes which contain particular Route Targets (RT). It would be beneficial for BGP speakers to know when the consequent routing update is completed. This document specifies an enhanced BGP End-of-RIB marker which can facilitate fine granular BGP route convergence in various BGP based network services. A new BGP capability to negotiate the usage of the enhanced End-of-RIB marker is also specified. 2. Enhanced End-of-RIB Marker The Enhanced End-of-RIB marker is similar to the End-of-RIB marker as defined in [RFC4724], which is an UPDATE message with no reachable Network Layer Reachability Information (NLRI) and empty withdrawn NLRI. In addition, the Enhanced End-of-RIB marker also contains a set of BGP Path Attributes which are used to identify a particular group of BGP routes for which the advertisement has completed. The Enhanced End-of-RIB marker can be used to indicate the completion of routing update for specific route groups. One typical example of the group is routes of a specific VPN customer, which is identified by the RTs of the VPN. 3. BGP Enhanced End-of-RIB Capability A new BGP capability called 'Enhanced End-of-RIB' Capability is defined. The Capability code for this capability is to be assigned. The Capability length field is zero. By advertising this capability to a peer, a BGP speaker conveys to the peer that the speaker support advertising and receiving the Enhanced End-of-RIB marker and the related procedures described in this document. After capability negotiation, if both the peer speaker and local speaker support this capability, the Enhanced End- of-RIB can be used to facilitate fine granular route convergence. 4. Usage of Enhanced End-of-RIB Marker As an enhancement to the existing End-of-RIB marker [RFC4724], the advertisement of Enhanced End-of-RIB marker can be used for fine granular route convergence of specific route groups within a specific address family. One typical scenario is to use the Enhanced End-of- RIB marker as the indication of routing update completion of specific VPN customer. In such case, the Enhanced End-of-RIB marker SHOULD carry the Extended Communities attribute which contains the RTs of the VPN. There are also other use cases of fine granular BGP route Dong Expires April 21, 2016 [Page 3] Internet-Draft Enhanced BGP End-of-RIB Marker October 2015 convergence, which is for further study and not included in current version of this document. The Enhanced End-of-RIB marker may be used only for a subset of VPN customers which require faster route convergence, selection of such VPN customers is based on the operator's policy. When the route advertisement for such VPN customers is completed, the sending BGP speaker MUST send the Enhanced End-of-RIB marker with RTs identifying the VPN customers to the peer. The receiving BGP speaker SHOULD use the Enhanced End-of-RIB marker as the trigger of route selection and further processing of routes of the identified VPN customers. The Enhanced End-of-RIB can be used for both the initial routing update and the routing updates triggered by the update of RT membership information [RFC4684], while the traditional End-of-RIB marker SHOULD still be used to indicate the completion of routing updates for the whole address family. 5. IANA Considerations A new BGP capability - Enhanced End-of-RIB Capability is defined in this document. The Capability code needs to be assigned by the IANA. 6. Security Considerations Procedures and protocol extensions defined in this document do not affect the BGP security model. See [RFC6952] for details. 7. Acknowledgements TBD 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, . Dong Expires April 21, 2016 [Page 4] Internet-Draft Enhanced BGP End-of-RIB Marker October 2015 [RFC4724] Sangli, S., Chen, E., Fernando, R., Scudder, J., and Y. Rekhter, "Graceful Restart Mechanism for BGP", RFC 4724, DOI 10.17487/RFC4724, January 2007, . 8.2. Informative References [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006, . [RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk, R., Patel, K., and J. Guichard, "Constrained Route Distribution for Border Gateway Protocol/MultiProtocol Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual Private Networks (VPNs)", RFC 4684, DOI 10.17487/RFC4684, November 2006, . [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, . Author's Address Jie Dong Huawei Technologies Huawei Campus, No.156 Beiqing Rd. Beijing 100095 China Email: jie.dong@huawei.com Dong Expires April 21, 2016 [Page 5]