Alexandre Snarskii <snar@snar.spb.ru> wrote:

AGGREGATOR is an optional transitive attribute of length 6. The attribute contains the last AS number that formed the aggregate route (encoded as 2 octets), followed by the IP address of the BGP speaker that formed the aggregate route (encoded as 4 octets). Usage of this attribute is described in 5.1.7

And what to do with 4-byte AS-numbers then? That would explain the 8 bytes.

Hi, we also have some issues with this here, the update message the Redback logged is: ffff ffff ffff ffff ffff ffff ffff ffff 0049 02 0000 002e 4001 01 00 4002 12 02 04 00000513 00000d1c 0000b611 0000b611 4003 04 50ef82c1 4006 00 c007 08 00 0000 0000 0000 00 16 ce7d a4 The prefix is 206.125.164.0/22, AS-PATH is 1299 3356 46609 46609 (Telia, Level3, and finally Hostlogistic with one prepend). The AGGREGATOR is full of 0. I guess this could be what bothers the Redback/Ericsson code. I see the same route by other sessions, and the aggregator looks OK, since the sh bgp says: 206.125.164.0/22 [...] 8218 4436 46609 46609 [...] Origin incomplete, localpref 100, med 100, weight 100, external, best aggregator: 206.125.165.242, AS 46609, atomic-aggregate So Hostlogistic route to Level3 is malformed (according to the RFC, the AGGREGATOR content is mandatory if the attribute is present), but their route to NLayer is OK. Or maybe a Level3 router has a problem? Anyway, our Redback/Ericsson routers are the problem now, since the other vendors don't throw away the BGP sessions... I've opened a case at Ericsson, still waiting for an answer :-/ regards, Olivier Benghozi Wifirst