BGP: Malformed attribute list

[Ondrej Zajicek]

On Thu, Apr 08, 2010 at 02:44:11PM +0200, Wolfgang Hennerbichler wrote:
> Allright, reply to myself: 
> 
> This seems to be a bug in BIRD. 
> What I actually added was a rule that certain communities should be deleted: 
> if ((1120,1)) ~ bgp_community then bgp_community.delete((1120,1));
> 
> this actually seemed to delete the only community attached to a
> certain prefix, which led to a bgp announcement that contained the
> community attribute which was in fact empty. this causes some cisco
> routers to throw up on the bgp session. So I think this is a bug in BIRD
> - if the last community is deleted on a prefix, the community tag must
> no longer be attached to the prefix. What do you think? Are there any
> chances you could fix this in the coming update? 

Hello.

Thank you for the bug report. The RFC 1997 does not explicitly forbid
empty community attribute and we assumed that it is valid. But if
some Cisco routers don't like it reasonable to not generate such
attribute. I fixed it in dev version and the fix will be in coming
update.

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Digital signature
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20100409/32fbf964/attachment-0001.asc>