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 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 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 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. Jakma Expires March 23, 2012 [Page 1] Internet-Draft BGP MRAI Timer Revision September 2011 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 Jakma Expires March 23, 2012 [Page 2] Internet-Draft BGP MRAI Timer Revision September 2011 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. Jakma Expires March 23, 2012 [Page 3] Internet-Draft BGP MRAI Timer Revision September 2011 [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 Jakma Expires March 23, 2012 [Page 4]