[14158] in North American Network Operators' Group
Re: IBGP problem concerning more specific routes
daemon@ATHENA.MIT.EDU (Vincent J. Bono)
Wed Dec 3 12:04:50 1997
From: "Vincent J. Bono" <vbono@comstor.com>
To: ppetit@synet.fr
Date: Thu, 3 Jan 1980 12:51:32 +0000
Reply-to: vbono@comstor.com
CC: nanog@merit.edu
In-reply-to: <199712022009.PAA16530@merit.edu>
Routes heard from EBGP only travel one hop into your network when
exported via IBGP. But, this should meet that criteria. Have you
done anything with localpref values or weights? It may be that R2 is
ignoring the specificity of the /24 in deference to the AS Path and
Local AS number of the /16.
-v
> From: "Pascal Petit - SYNET" <ppetit@synet.fr>
> To: <nanog@merit.edu>
> Subject: IBGP problem concerning more specific routes
> Date: Tue, 2 Dec 1997 21:03:53 +0100
> Reply-to: ppetit@synet.fr
> Here is an amusing BGP problem :
>
>
> Wild Wolrd-----------R1--------------R2------Our Networks
>
> There is an IBGP sesion running between R1 and R2. R2 advertises route
> 194.214.0.0/16 to R1. In our block there is a class C used by one of our
> customer which is not directly connected to our network. This customer
> advertises its class C to the Wild World via its own ISP.
>
> R1 receives the 194.214.253.0/24 advertisement from the Wild World, it
> stores it in its routing table; however R2 never takes it into account :
> its routing table only mentions 194.214.0.0/16 , it doesn't mention the
> more specific routing entry 194.214.253.0/24.
>
> Our Networks cannot get to 194.214.253.0/24. Is it a feature of IBGP ??
>
> Thanks for any help,
>
> Pascal
>
>
> ------------------------------------------------------------------------
> Pascal Petit
> SYNET tel: 33 1 4696 0040
> 74, rue Roque de Fillol fax: 33 1 4696 0041
> 92800 Puteaux email: ppetit@synet.fr
> FRANCE http://www.synet.fr
>
>
