Still working on my problem.
When doing a tcpdumpc apture of bgp UPDATE messages sent to neighbor 2
(2-bytes AS), I still have
/Update Message (2), length: 54//
// Origin (1), length: 1, Flags [T]: IGP//
// 0x0000: 00//
// AS Path (2), length: 4, Flags [T]: *23456 *//
// 0x0000: 0201 5ba0//
// Next Hop (3), length: 4, Flags [T]: 192.168.x.x//
// 0x0000: c0a8 3571//
// AS4 Path (17), length: 6, Flags [OT]: <my 4bytes AS>//
// 0x0000: 0201 0003 039c//
// Updated routes://
// 46.226.x.x/21//
/
Why is AS 23456 still here ? Shouldn't it be replaced with my 2bytes AS ?
Regards,
Cédric
Le 29/07/2013 09:33, OCEANET - Cédric BASSAGET a écrit :
> Hello,
>
> I'm trying to replace two cisco routers by two openBGPd routers.
> A have 3 neighbors, two with 4-bytes AS, and one which only supports
> 2-bytes AS for now.
> I have a 4-bytes AS too.
>
> So in my bgpd.conf, I have :
>
> ...
> AS <my 4bytes> <a 2bytes AS>
> network z.z.z.z/21
> ...
> neighbor <neighbor's ip address> #a neighbor which supports 4 bytes AS
> {
> remote-as <neighbor's AS>
> set prepend-self 1
> }
> ...
> neighbor <neighbor's ip address> #a neighbor which supports 2 bytes
> AS only
> {
> remote-as <neighbor's AS>
> set prepend-self 2
> }
> ...
>
> My problem is that my second neighbor return this message :
>
> neighbor : received notification: error in UPDATE message, AS-Path
> unacceptable
>
> I think bgpd is trying to prepend the neighbor which does not support
> 4bytes AS with... a 4 bytes AS, due to the "set prepend-self 2".
>
> Now, time for the questions :
> - Is it openBGPd's normal behavior ?
> - Is there a way to force prepending with the 2 bytes AS ? I saw
> "announce as-4byte (yes|no)" in manpage, is this option designed for
> that ?
>
> Thanks for your replies.
> Regards,
> Cédric
>
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OCEANET
---------------------------------------------------------------
[AGENCE DU MANS]
7, rue des Frênes
ZAC de la Pointe
72190 SARGE LES LE MANS
[t] +33 (0)2.43.50.26.50
[f] +33 (0)2.43.72.21.14
[AGENCE D'ANGERS]
5, rue Fleming
Angers Technopole
49066 ANGERS
[t] +33 (0)2.41.19.28.65
[f] +33 (0)2.52.19.22.00
http://www.oceanet.com
http://www.oceanet-telecom.com
