[47737] in North American Network Operators' Group
Re: BGP and aggregation
daemon@ATHENA.MIT.EDU (Richard A Steenbergen)
Sat May 11 17:55:39 2002
Date: Sat, 11 May 2002 17:52:36 -0400
From: Richard A Steenbergen <ras@e-gerbil.net>
To: Ralph Doncaster <ralph@istop.com>
Cc: nanog@merit.edu
Message-ID: <20020511215236.GW375@overlord.e-gerbil.net>
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On Sat, May 11, 2002 at 05:34:39PM -0400, Ralph Doncaster wrote:
>
> I have transit in 2 cities. I have a circuit connecting the 2 cities as
> well. So far I've been using non-contiguous IPs, so there's been no
> opportunity for aggregation. Having just received my /20 from ARIN, I'm
> trying to plan my network. Lets say I split the /20 into 2 /21's, one for
> each city. I'd like to announce the aggregate /20 instead of 2 /21's, as
> long as the circuit connecting the 2 cities is working. If the circuit
> goes down I want each city to announce the local /21. Is this
> possible? (using either a Cisco router or Zebra)
If I was paying for transit, I would want THEM to do the work of
delivering it to the right city, without wasting the bandwidth of my
circuit (unless they're really close and that circuit is really cheap).
If you're using the same transit provider in both cities, how about
announcing the /20, and the 2 /21s tagged with no-export. The /20 would be
heard by the world and get the traffic to your transit provider, then the
/21s would route it to the right exit point.
--
Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177 (67 29 D7 BC E8 18 3E DA B2 46 B3 D8 14 36 FE B6)
