The Accumulated IGP Metric Attribute for BGP
RFC 7311
Document | Type |
RFC - Proposed Standard
(August 2014; No errata)
Was draft-ietf-idr-aigp (idr WG)
|
|
---|---|---|---|
Authors | Prodosh Mohapatra , Rex Fernando , Eric Rosen , Jim Uttaro | ||
Last updated | 2015-10-14 | ||
Replaces | draft-rosen-idr-aigp | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Susan Hares | ||
Shepherd write-up | Show (last changed 2014-03-04) | ||
IESG | IESG state | RFC 7311 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Alia Atlas | ||
Send notices to | (None) | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) P. Mohapatra Request for Comments: 7311 Sproute Networks Category: Standards Track R. Fernando ISSN: 2070-1721 E. Rosen Cisco Systems, Inc. J. Uttaro AT&T August 2014 The Accumulated IGP Metric Attribute for BGP Abstract Routing protocols that have been designed to run within a single administrative domain (IGPs) generally do so by assigning a metric to each link and then choosing, as the installed path between two nodes, the path for which the total distance (sum of the metric of each link along the path) is minimized. BGP, designed to provide routing over a large number of independent administrative domains (autonomous systems), does not make its path-selection decisions through the use of a metric. It is generally recognized that any attempt to do so would incur significant scalability problems as well as inter- administration coordination problems. However, there are deployments in which a single administration runs several contiguous BGP networks. In such cases, it can be desirable, within that single administrative domain, for BGP to select paths based on a metric, just as an IGP would do. The purpose of this document is to provide a specification for doing so. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7311. Mohapatra, et al. Standards Track [Page 1] RFC 7311 AIGP Metric Attribute for BGP August 2014 Copyright Notice Copyright (c) 2014 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. Table of Contents 1. Introduction ....................................................3 2. Specification of Requirements ...................................4 3. AIGP Attribute ..................................................4 3.1. Applicability Restrictions and Cautions ....................6 3.2. Handling a Malformed AIGP Attribute ........................6 3.3. Restrictions on Sending/Receiving ..........................6 3.4. Creating and Modifying the AIGP Attribute ..................7 3.4.1. Originating the AIGP Attribute ......................7 3.4.2. Modifications by the Originator .....................8 3.4.3. Modifications by a Non-Originator ...................8 4. Decision Process ...............................................10 4.1. When a Route Has an AIGP Attribute ........................11 4.2. When the Route to the Next Hop Has an AIGP Attribute ......11 5. Deployment Considerations ......................................12 6. IANA Considerations ............................................13 7. Security Considerations ........................................13 8. Acknowledgments ................................................13 9. References .....................................................14 9.1. Normative Reference .......................................14 9.2. Informative References ....................................14 Mohapatra, et al. Standards Track [Page 2] RFC 7311 AIGP Metric Attribute for BGP August 2014 1. Introduction There are many routing protocols that have been designed to run within a single administrative domain. These are known collectively as "Interior Gateway Protocols" (IGPs). Typically, each link is assigned a particular "metric" value. The path between two nodes canShow full document text