Internet DRAFT - draft-ietf-idr-mrai-dep

draft-ietf-idr-mrai-dep






Inter-Domain Routing                                            P. Jakma
Internet-Draft                              School of Computing Science,
Updates: 4271 (if approved)                              Uni. of Glasgow
Intended status: Standards Track                      September 20, 2011
Expires: March 23, 2012


      Revisions to the BGP 'Minimum Route Advertisement Interval'
                       draft-ietf-idr-mrai-dep-04

Abstract

   This document updates the specification of the BGP MRAI timer in
   [RFC4271], by deprecating the previously recommended values and by
   allowing for withdrawals to be exempted from the MRAI.

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
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   This Internet-Draft will expire on March 23, 2012.

Copyright Notice

   Copyright (c) 2011 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
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   described in the Simplified BSD License.




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Table of Contents

   1.  Requirements Language . . . . . . . . . . . . . . . . . . . . . 3
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Revision  . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . . . 3
   6.  Normative References  . . . . . . . . . . . . . . . . . . . . . 3
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 4










































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1.  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 [RFC2119].


2.  Background

   The Minimum Route Advertisement Interval (MRAI) timer is specified in
   [RFC4271].  This timer acts to rate-limit updates, on a per-
   destination basis.  [RFC4271] suggests values of 30s and 5s for this
   interval for eBGP and iBGP respectively.  The MRAI must also be
   applied to withdrawals according to RFC4271, a change from the
   earlier RFC1771.

   The MRAI timer has a significant effect on the convergence of BGP, in
   terms of convergence time, the number of messages, amongst other
   metrics.  The optimum value for this timer is hard to estimate, never
   mind calculate and will differ between networks, and probably even
   different subsets of the same network.


3.  Revision

   The suggested default values for the
   MinRouteAdvertisementIntervalTimer given in [RFC4271] are deprecated.
   The appropriate choice of default values is left to the discretion of
   implementors.  Implementations SHOULD provide a means to allow
   operators to choose values appropriate to their requirements, on a
   per-peer and per-AFI/SAFI basis.  Implementations MAY exempt
   withdrawals from the MRAI timer.


4.  IANA Considerations

   There are no requests made to IANA in this document.


5.  Security Considerations

   This document raises no new security considerations.


6.  Normative References

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



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


Author's Address

   Paul Jakma
   School of Computing Science, Uni. of Glasgow
   Sir Alwyn Williams Building
   Glasgow  G12 8QQ
   Scotland

   Email: paulj@dcs.gla.ac.uk






































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