[76390] in North American Network Operators' Group
Re: Peering best practices advice needed.
daemon@ATHENA.MIT.EDU (David Gethings)
Thu Dec 9 06:16:10 2004
From: David Gethings <davidg@pipex.net>
Reply-To: davidg@pipex.net
To: Rolo Tomassi <rolotomassi32@hotmail.com>
Cc: nanog@merit.edu
In-Reply-To: <BAY17-F259483B1EB2E37F86F5478AEB60@phx.gbl>
Date: Thu, 09 Dec 2004 11:15:09 +0000
Errors-To: owner-nanog-outgoing@merit.edu
On Wed, 2004-12-08 at 17:03 +0000, Rolo Tomassi wrote:
> Hi all,
>
> Please forgive the simplistic nature of the query..
>
> Basically my company is multi-homed with 2 different providers in the UK,
> and advertising a /18. Now some colleaguges in another part of the world
> want to break that /18 into two /19's and advertise one /19 and we advertise
> the other. This is fine, however we are NOT running IBGP in the core,
> therefore the UK customers in the /19 will not be able to reach the other
> /19 as there would be a loop detected through EBGP.
>
> Now someone mentioned that we could use AS-LOOP-IN feature which will
> overcome this problem and allow us to route to each other via EBGP. I really
> think this is a bad idea but until we get an internal link - I dont see a
> way forward. So... anyone doing this currently in their network or have any
> "best practices" way round this. I want our company to be good Netizens but
> still be able to pass traffic between the 2 /19's.
Well another way for solve this problem is that both parts advertise
their /19. From the transit provider take your normal routing table and
a default route. The default route allows the two /19's to reach each
other over the transit provider(s).
--
Cheers
Dg
