Network Working Group                                           K. Patel
Internet-Draft                                             Cisco Systems
Intended status: Standards Track                                 D. Ward
Expires: September 8, 2011                              Juniper Networks
                                                                 R. Bush
                                                                     IIJ
                                                           March 7, 2011


                    Extended Message support for BGP
                  draft-ymbk-bgp-extended-messages-00

Abstract

   The current BGP specification mandates a maximum BGP message size of
   4096 octets.  As BGP is extended to support newer AFI/SAFIs, there is
   a need to extend the maximum message size beyond 4096 octets.  This
   draft provides an extension for BGP to extend its current message
   size for BGP messages from 4096 octets to 65535 octets.

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 September 8, 2011.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.




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   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
   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  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Extended message Capability for BGP . . . . . . . . . . . . . . 3
   3.  Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   4.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   7.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 4






























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1.  Introduction

   The current BGP specification [RFC4271] mandates a maximum BGP
   message size of 4096 octets.  As BGP is extended to support newer
   AFI/SAFIs and newer capabilities, there is a need to extend the
   maximum message size beyond 4096 octets.  This draft provides an
   extension for BGP to extend its current message size for BGP messages
   from 4096 octets to 65535 octets.


2.  Extended message Capability for BGP

   To advertise BGP Extended Message Capability to a peer, a BGP speaker
   uses BGP Capabilities Advertisement [RFC3392].  By advertising the
   BGP Extended message Capability to a peer, a BGP speaker conveys to
   that peer that the speaker is capable of receiving and properly
   handling BGP Extended Messages.

   This is an asymmetric capability.  I.e. one speaker could signal the
   capability and the other not, so that extended messages could flow
   only in the direction toward the speaker which advertised the
   capability.

   The BGP Extended Message Capability is a new BGP Capability [RFC3392]
   defined with Capability code TBD and Capability length 0.


3.  Operation

   A BGP speaker that is willing to receive BGP Extended Messages from
   its peer should advertise the BGP Extended Message Capability to its
   peer using BGP Capabilities Advertisement [RFC3392].  A BGP speaker
   may send extended messages to its peer only if it has received the
   Extended Message Capability from its peer.

   All BGP extended messages have maximum message size of 65535 octets.
   The smallest message that may be sent consists of a BGP header
   without a data portion (19 octets).  All multi-octet fields are in
   network byte order.


4.  Acknowledgements

   The authors thank John Scudder for his input.







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5.  IANA Considerations

   This document defines the Extended Message Capability for BGP.  The
   new Capability code needs to be assigned by IANA.


6.  Security Considerations

   This extension to BGP does not change BGP's underlying security
   issues.


7.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3392]  Chandra, R. and J. Scudder, "Capabilities Advertisement
              with BGP-4", RFC 3392, November 2002.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.


Authors' Addresses

   Keyur Patel
   Cisco Systems
   170 W. Tasman Drive
   San Jose, CA  95134
   USA

   Email: keyupate@cisco.com


   Dave Ward
   Juniper Networks
   1194 N. Mathilda Ave
   Sunnyvale, CA  94089
   USA

   Email: dward@juniper.net









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   Randy Bush
   Internet Initiative Japan, Inc.
   5147 Crystal Springs
   Bainbridge Island, Washington  98110
   US

   Phone: +1 206 780 0431 x1
   Email: randy@psg.com











































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