[109832] in North American Network Operators' Group
Re: 91.207.218.0/23 prefix in DFZ - AS3.21 / AS196629 - announced
daemon@ATHENA.MIT.EDU (Florian Weimer)
Thu Dec 11 03:34:44 2008
To: Andy Davidson <andy@nosignal.org>
From: Florian Weimer <fweimer@bfk.de>
Date: Thu, 11 Dec 2008 09:34:27 +0100
In-Reply-To: <3A842311-ADB9-41D4-A419-65FDFF0D6A43@nosignal.org> (Andy
Davidson's message of "Wed, 10 Dec 2008 18:24:20 +0000")
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
* Andy Davidson:
> OpenBGPd is therefore dropping the sessions when this update is
> received. Unideal if this attribute is learned on multiple
> upstreams...
>
> The impact today is fairly limited as there are relatively few bgp
> speakers honouring the 4-byte ASN protocol extension rules, but as
> code that support these features creeps around the internet, the next
> time this happens the impact could be much greater, so we need to
> understand which implementation of which BGP software caused this
> illegal origination.
Uhm, shouldn't you just ignore invalid AS4_PATH attributes, instead of
dropping the session? It's a transient, optional attribute, so you
can't rely on your peers to filter it.
--=20
Florian Weimer <fweimer@bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstra=DFe 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99
