[rbak-nsp] SEOS 6.4.1.1 and iBGP problem

[David Freedman]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Well, I notice from this output the following:

>c0 0708 0000 611f 0000 0000

c0 - optional transitive attribute follows
07 - AGGREGATOR
08 - of 8 bytes
0000611f - from AS 24863
00000000 - aggregated by 0.0.0.0

According to RFC4271, sec 5.1.7:

   AGGREGATOR is an optional transitive attribute, which MAY be included
   in updates that are formed by aggregation (see Section 9.2.2.2).  A
   BGP speaker that performs route aggregation MAY add the AGGREGATOR
   attribute, which SHALL contain its own AS number and IP address.  The
   IP address SHOULD be the same as the BGP Identifier of the speaker.

It is possible that SEOS considers 0.0.0.0 to be an invalid BGP
identifier and therefore an impossible aggregator

For reference, this update covers the following prefixes:

41.178.0.0/24
41.196.4.0/22
41.196.8.0/22
41.196.12.0/22
41.196.16.0/22
41.196.24.0/22
41.196.36.0/23


with AS_PATH 24724 15412 24863

Since none of my SEOS boxes carry a full table can another SEOS operator
with a full table confirm if they have these prefixes (and if so, what
it shows as aggregator)

I can tell you in Cisco IOS, I accept these prefixes.

Dave


Blake Willis wrote:
> On Sep 27, 2010, at 2:12 PM, Marcin Kuczera wrote:
> 
>> [bgp1]se100-test#show bgp neighbor 195.66.73.253 malform update
>> Dump logged malformed UPDATE messages for ??? (1 total entries):
>> Sep 27 14:09:48 Malformed UPDATE msg (nbr 195.66.73.253, context
>> 0x40080002, 120 bytes, repeated 4221 times, reason: Invalid msg) -
>> ffff ffff ffff ffff ffff ffff ffff ffff 0078 0200 0000 4540 0101 02c0
>> 0708 0000 611f 0000 0000 5002 000e 0203 0000 6094 0000 3c34 0000 611f 4
>> 003 04c1 6f26 6180 0404 0000 0000 4005 0400 0000 c8c0 080c 0000 3b41
>> 0000 51cc 220a 220a 1829 b200 1629 c404 1629 c408 1629 c40c 1629 c410 162
>> 9 c418 1729 c424
> 
> Ouch.  I think it's time to open a case with the TAC.  Looks like we
> won't be testing 6.4 any time soon then...
> 
>> Is there any possibility to ignore malformed updates instead of
>> dropping down whole session ?
> 
> I don't think I've seen a knob like that from any vendor so far...
> 
>  -Blake
> _______________________________________________
> redback-nsp mailing list
> redback-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/redback-nsp
> 
7

- --

David Freedman
Group Network Engineering

david.freedman at uk.clara.net
Tel +44 (0) 20 7685 8000

Claranet Group
21 Southampton Row
London - WC1B 5HA - UK
http://www.claranet.com

Company Registration: 3152737 - Place of registration: England

All the information contained within this electronic message from
Claranet Ltd is covered by the disclaimer at
http://www.claranet.co.uk/disclaimer
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAkygpawACgkQtFWeqpgEZrIjlgCgxvGlXvKHoHjAaHctbJcRkjZY
Km0An2toSq7335aZe/ThGR6gy+JeVA4e
=rYl4
-----END PGP SIGNATURE-----