[c-nsp] Cogent IOS upgrade == BGP-3, "update malformed"

Zoe O'Connell zoe-nsp at complicity.co.uk
Mon Aug 23 08:34:50 EDT 2010


On 23/08/10 13:07, Florian Weimer wrote:
> * Zoe O'Connell:
>
>   
>>> 729078: Aug 22 16:21:39 MDT: %BGP-3-NOTIFICATION: sent to neighbor A.B.C.D
>>> 3/1 (update malformed) 21 bytes 31FE420C 31FE58C8 124683E8 0206CC67 00
>>> 729079: Aug 22 16:21:39 MDT: BGP: A.B.C.D Bad attributes FFFF FFFF FFFF FFFF
>>> FFFF FFFF FFFF FFFF 0060 0200 0000 4140 0101 0040 020C 0205 00AE 0CB9 235A
>>> 2046 5BA0 4003 0426 6532 7580 0404 0000 5DE8 C008 0800 AE52 0800 AE55 FD31
>>> FE42 0C31 FE58 C812 4683 E802 06CC 6700 0000 0002 1854 1608 1854 1609
>>>       
> 5BA0 suggests its related to 32 bit ASNs.  We've got the prefixes in
> our table, apparently with a proper 32-bit ASN:
>   

Yes, that's the conclusion we came to as well when we had it. (Luckily,
it was an iBGP link to a firewall so easier to troubleshoot than a
customer link). As far as I can recall, without Capability Negotiation
it can't send 4-byte ASNs and some devices have a bug or differing RFC
interpretation that means they can't handle being on the receiving end
properly - if Cogent won't change their end, an IOS upgrade on the
original psoters end should resolve it. I'm sure I sent a mail to
someone about it at the time with more precise detail, but I can't seem
to find it now.


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