BGP and aggregation
E.B. Dreger
eddy+public+spam at noc.everquick.net
Sat May 11 21:58:51 UTC 2002
RD> Date: Sat, 11 May 2002 17:34:39 -0400 (EDT)
RD> From: Ralph Doncaster
RD> I have transit in 2 cities. I have a circuit connecting the
RD> 2 cities as well. So far I've been using non-contiguous IPs,
RD> so there's been no opportunity for aggregation. Having just
RD> received my /20 from ARIN, I'm trying to plan my network.
RD> Lets say I split the /20 into 2 /21's, one for each city.
RD> I'd like to announce the aggregate /20 instead of 2 /21's, as
RD> long as the circuit connecting the 2 cities is working. If
RD> the circuit goes down I want each city to announce the local
RD> /21. Is this possible? (using either a Cisco router or
RD> Zebra)
* BGP is an EGP, not an IGP
* You might want to check out OSPF if you think your net will
grow
* You don't want your IGP influencing your EGP. Flap, flap.
* Redistributing EGP into IGP isn't exactly good, either.
Are the upstreams the same in each city? Why not announce the
aggregate /20 normally, and set NO_REDISTRIBUTE and use MEDs on
the /21s? You're paying for transit, so MEDs are fair game.
--
Eddy
Brotsman & Dreger, Inc. - EverQuick Internet Division
Phone: +1 (316) 794-8922 Wichita/(Inter)national
Phone: +1 (785) 865-5885 Lawrence
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Date: Mon, 21 May 2001 11:23:58 +0000 (GMT)
From: A Trap <blacklist at brics.com>
To: blacklist at brics.com
Subject: Please ignore this portion of my mail signature.
These last few lines are a trap for address-harvesting spambots.
Do NOT send mail to <blacklist at brics.com>, or you are likely to
be blocked.
More information about the NANOG
mailing list