backup relationships possibly harmful

Fri Jun 8 00:03:16 UTC 2001

in the paper by gao, griffin, and rexford, it is shown that backup
transit low-pref relationships as done today can lead to routing loops.
it's worth a look just for that.

while the authors propose a protocol approach, i wonder if there is an
operational approach.

randy

---

From: Jennifer Rexford <jrex at research.att.com>
To: randy at research.att.com
Cc: griffin at research.att.com
Subject: backup relationships
Date: Wed, 6 Jun 2001 15:24:31 -0400 (EDT)

Randy,

Following up on our conversation this afternoon about backup routes
and convergence problems, see

  Lixin Gao, Tim Griffin, and Jennifer Rexford, "Inherently safe
  backup routing with BGP," Proc. IEEE INFOCOM, April 2001.
    http://www.research.att.com/~jrex/papers/infocom01.ps

and the slides at

  http://www.research.att.com/~jrex/talks/infocom01.ps
  http://www.research.att.com/~jrex/talks/infocom01.ppt

The slides give a relatively theory-free overview.  The intro of the
paper presents the problem and the key results of the paper, and the
body of the paper has some examples worked out and a fair amount of
Greek to prove that our proposals handle the problem.

The paper builds on earlier work by Tim on the stable paths problem
(INFOCOM'00) and the non-convergence of some BGP configurations
(SIGCOMM'99), and by Lixin and me on showing how policies based on
peer-peer and customer-provider relationships can prevent these
problems (SIGMETRICS'00).  Backup routes throw a wrench into the work
that Lixin and I did; this INFOCOM'01 paper proposes a way to deal
with that problem.  See the section on "global sanity of BGP routing"
at http://www.research.att.com/~griffin/interdomain.html#divergepapers
for the papers.

-- Jen