draft-ietf-idr-bgp-extended-messages-23.txt   draft-ietf-idr-bgp-extended-messages-24.txt 
Network Working Group R. Bush Network Working Group R. Bush
Internet-Draft Internet Initiative Japan Internet-Draft Internet Initiative Japan
Updates: 4271 (if approved) K. Patel Updates: 4271 (if approved) K. Patel
Intended status: Standards Track Arrcus, Inc. Intended status: Standards Track Arrcus, Inc.
Expires: May 1, 2018 D. Ward Expires: May 23, 2018 D. Ward
Cisco Systems Cisco Systems
October 28, 2017 November 19, 2017
Extended Message support for BGP Extended Message support for BGP
draft-ietf-idr-bgp-extended-messages-23 draft-ietf-idr-bgp-extended-messages-24
Abstract Abstract
The BGP specification mandates a maximum BGP message size of 4096 The BGP specification mandates a maximum BGP message size of 4096
octets. As BGP is extended to support newer AFI/SAFIs and other octets. As BGP is extended to support newer AFI/SAFIs and other
features, there is a need to extend the maximum message size beyond features, there is a need to extend the maximum message size beyond
4096 octets. This document updates the BGP specification RFC4271 by 4096 octets. This document updates the BGP specification RFC4271 by
providing an extension to BGP to extend its current maximum message providing an extension to BGP to extend its current maximum message
size from 4096 octets to 65535 octets for all except the OPEN size from 4096 octets to 65535 octets for all except the OPEN
message. message.
skipping to change at page 1, line 47 skipping to change at page 1, line 47
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 1, 2018. This Internet-Draft will expire on May 23, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 26 skipping to change at page 2, line 26
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. BGP Extended Message . . . . . . . . . . . . . . . . . . . . 2 2. BGP Extended Message . . . . . . . . . . . . . . . . . . . . 2
3. Extended message Capability for BGP . . . . . . . . . . . . . 3 3. Extended message Capability for BGP . . . . . . . . . . . . . 3
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 3 5. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4
6. Changes to RFC4271 . . . . . . . . . . . . . . . . . . . . . 4 6. Changes to RFC4271 . . . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8. Security Considerations . . . . . . . . . . . . . . . . . . . 4 8. Security Considerations . . . . . . . . . . . . . . . . . . . 4
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
10.1. Normative References . . . . . . . . . . . . . . . . . . 5 10.1. Normative References . . . . . . . . . . . . . . . . . . 5
10.2. Informative References . . . . . . . . . . . . . . . . . 5 10.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
The BGP specification [RFC4271] mandates a maximum BGP message size The BGP specification [RFC4271] mandates a maximum BGP message size
of 4096 octets. As BGP is extended to support newer AFI/SAFIs and of 4096 octets. As BGP is extended to support newer AFI/SAFIs and
newer capabilities (e.g., [I-D.ietf-sidr-bgpsec-protocol]), there is newer capabilities (e.g., [I-D.ietf-sidr-bgpsec-protocol]), there is
a need to extend the maximum message size beyond 4096 octets. This a need to extend the maximum message size beyond 4096 octets. This
draft provides an extension to BGP to extend its current message size draft provides an extension to BGP to extend its current message size
limit from 4096 octets to 65535 octetsfor all except the OPEN limit from 4096 octets to 65535 octetsfor all except the OPEN
message. message.
2. BGP Extended Message 2. BGP Extended Message
A BGP message over 4096 octets in length is a BGP Extended Message. A BGP message over 4096 octets in length is a BGP Extended Message.
BGP Extended Messages have maximum message size of 65535 octets. The BGP Extended Messages have maximum message size of 65535 octets. The
smallest message that may be sent consists of a BGP header without a smallest message that may be sent consists of a BGP header without a
data portion (19 octets). data portion (19 octets).
Multi-octet fields MUST be in network byte order.
3. Extended message Capability for BGP 3. Extended message Capability for BGP
To advertise the BGP Extended Message Capability to a peer, a BGP To advertise the BGP Extended Message Capability to a peer, a BGP
speaker uses BGP Capabilities Advertisement [RFC5492]. By speaker uses BGP Capabilities Advertisement [RFC5492]. By
advertising the BGP Extended Message Capability to a peer, a BGP advertising the BGP Extended Message Capability to a peer, a BGP
speaker conveys that it is able to send, receive, and properly handle speaker conveys that it is able to send, receive, and properly handle
BGP Extended Messages. BGP Extended Messages.
A peer which does not advertise this capability MUST NOT send BGP A peer which does not advertise this capability MUST NOT send BGP
Extended Messages, and BGP Extended Messages MUST NOT be sent to it. Extended Messages, and BGP Extended Messages MUST NOT be sent to it.
skipping to change at page 3, line 47 skipping to change at page 3, line 45
Applications generating information which might be encapsulated Applications generating information which might be encapsulated
within BGP messages MUST limit the size of their payload to take the within BGP messages MUST limit the size of their payload to take the
maximum message size into account. maximum message size into account.
A BGP announcement will, in the normal case, propagate throughout the A BGP announcement will, in the normal case, propagate throughout the
BGP speaking Internet; and there will undoubtedly be BGP speakers BGP speaking Internet; and there will undoubtedly be BGP speakers
which do not have the Extended Message capability. Therefore putting which do not have the Extended Message capability. Therefore putting
an attribute which can not be decomposed to 4096 octets or less in an an attribute which can not be decomposed to 4096 octets or less in an
Extended Message is a likely path to routing failure. Extended Message is a likely path to routing failure.
It is RECOMMENDED that BGP protocol developers and implementers are
conservative in their application and use of Extended Messages.
Future protocol specifications will need to describe how to handle
peers which can only accomodate 4096 octet messages.
5. Error Handling 5. Error Handling
A BGP speaker that has the ability to use Extended Messages but has A BGP speaker that has the ability to use Extended Messages but has
not advertised the BGP Extended Messages capability, presumably due not advertised the BGP Extended Messages capability, presumably due
to configuration, SHOULD NOT accept an Extended Message. A speaker to configuration, SHOULD NOT accept an Extended Message. A speaker
MAY implement a more liberal policy and accept Extended Messages, MAY implement a more liberal policy and accept Extended Messages,
even from a peer to which it has not advertised the capability, in even from a peer to which it has not advertised the capability, in
the interest of preserving the BGP session if at all possible. the interest of preserving the BGP session if at all possible.
A BGP speaker that does not advertise the BGP Extended Messages A BGP speaker that does not advertise the BGP Extended Messages
skipping to change at page 5, line 49 skipping to change at page 6, line 11
[I-D.ietf-sidr-bgpsec-protocol] [I-D.ietf-sidr-bgpsec-protocol]
Lepinski, M., "BGPSEC Protocol Specification", draft-ietf- Lepinski, M., "BGPSEC Protocol Specification", draft-ietf-
sidr-bgpsec-protocol-07 (work in progress), February 2013. sidr-bgpsec-protocol-07 (work in progress), February 2013.
Authors' Addresses Authors' Addresses
Randy Bush Randy Bush
Internet Initiative Japan Internet Initiative Japan
5147 Crystal Springs 5147 Crystal Springs
Bainbridge Island, Washington 98110 Bainbridge Island, Washington 98110
US United States of America
Email: randy@psg.com Email: randy@psg.com
Keyur Patel Keyur Patel
Arrcus, Inc. Arrcus, Inc.
Email: keyur@arrcus.com Email: keyur@arrcus.com
Dave Ward Dave Ward
Cisco Systems Cisco Systems
170 W. Tasman Drive 170 W. Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
USA United States of America
Email: dward@cisco.com Email: dward@cisco.com
 End of changes. 11 change blocks. 
10 lines changed or deleted 14 lines changed or added

This html diff was produced by rfcdiff 1.46. The latest version is available from http://tools.ietf.org/tools/rfcdiff/