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BGP Optimal Route Reflection (BGP-ORR)
draft-ietf-idr-bgp-optimal-route-reflection-06

Document type: Active Internet-Draft (idr WG)
Document stream: IETF
Last updated: 2014-01-02
Intended RFC status: Unknown
Other versions: plain text, pdf, html

IETF State: WG Document
Consensus: Unknown
Document shepherd: No shepherd assigned

IESG State: I-D Exists
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IDR Working Group                                              R. Raszuk
Internet-Draft                                                    NTT I3
Intended status: Standards Track                               C. Cassar
Expires: July 6, 2014                                      Cisco Systems
                                                                 E. Aman
                                                             TeliaSonera
                                                             B. Decraene
                                                            S. Litkowski
                                                                  Orange
                                                         January 2, 2014

                 BGP Optimal Route Reflection (BGP-ORR)
             draft-ietf-idr-bgp-optimal-route-reflection-06

Abstract

   [RFC4456] asserts that, because the Interior Gateway Protocol (IGP)
   cost to a given point in the network will vary across routers, "the
   route reflection approach may not yield the same route selection
   result as that of the full IBGP mesh approach."  One practical
   implication of this assertion is that the deployment of route
   reflection may thwart the ability to achieve hot potato routing.  Hot
   potato routing attempts to direct traffic to the closest AS egress
   point in cases where no higher priority policy dictates otherwise.
   As a consequence of the route reflection method, the choice of exit
   point for a route reflector and its clients will be the egress point
   closest to the route reflector - and not necessarily closest to the
   RR clients.

   Section 11 of [RFC4456] describes a deployment approach and a set of
   constraints which, if satsified, would result in the deployment of
   route reflection yielding the same results as the iBGP full mesh
   approach.  Such a deployment approach would make route reflection
   compatible with the application of hot potato routing policy.

   As networks evolved to accommodate architectural requirements of new
   services, tunneled (LSP/IP tunneling) networks with centralized route
   reflectors became commonplace.  This is one type of common deployment
   where it would be impractical to satisfy the constraints described in
   Section 11 of [RFC4456].  Yet, in such an environment, hot potato
   routing policy remains desirable.

   This document proposes two new solutions which can be deployed to
   facilitate the application of closest exit point policy centralized
   route reflection deployments.

Raszuk, et al.            Expires July 6, 2014                  [Page 1]
Internet-Draft        bgp-optimal-route-reflection          January 2014

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 July 6, 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
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   (http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Proposed solutions  . . . . . . . . . . . . . . . . . . . . .   5
   3.  Best path selection for BGP hot potato routing  from
       customized IGP network position . . . . . . . . . . . . . . .   6
     3.1.  Client's perspective best path selection algorithm  . . .   7
       3.1.1.  Flat IGP network  . . . . . . . . . . . . . . . . . .   7
       3.1.2.  Hierarchical IGP network  . . . . . . . . . . . . . .   8
     3.2.  Aside: Configuration-based flexible route reflector
           placement . . . . . . . . . . . . . . . . . . . . . . . .   9
     3.3.  Route reflector client grouping . . . . . . . . . . . . .  10

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