[..snip..]

Karsten,

thats really an interesting question:

ACOnet receives a full routing-table from SPRINT/AS1239 and from GEANT/AS20965. Comparing the current BGP session counters:

neighbor SPRINT, uptime ~20weeks, Received 7926940 messages neighbor GEANT, uptime ~ 7weeks, Received 29597194 messages

which gives a long-term average of

419 BGP update messages per minute from GEANT but only 39 BGP update messages per minute from SPRINT

afaik GEANT does no BGP flap damping, SPRINT however does, according to http://www.sprint.net/policy/bgpdamp.html

I don't know if damping is the only reason for the factor

...

10 between them, there might be other reasons as well, e.g. SPRINT backbone is Cisco based, GEANT is Juniper based and they might be using completely different IGPs and iBGP concepts.

It could also be due to the fact that SPRINT certainly constrains (or used to constrain) the maximum prefix length it will accept (not longer than /24 - used to be /18 I think but that was way too restrictive). Don't know about GEANT? Logically, you'd expect smaller blocks to be flapped more than larger aggregates so removing the smaller blocks entirely from what you accept/announce would reduce the number of announcements/withdrawls you make (even taking flap damping into account). It might be worth looking at the relative size of the "full" routing tables you receive from SPRINT and GEANT. If it's more from GEANT, that might be the answer. Regards, Guy --- Guy Davies Telindus IP Architect Hatchwood Place, Farnham Road, Odiham, Hants, RG29 1AB E: guy.davies@telindus.co.uk T: +44 (0)1256 709285 M: +44 (0)7879 434214 Yahoo!: aguyd2000@yahoo.com MSN: aguyd2000@hotmail.com AIM: aguyd2000 ICQ: 169876941 Jabber: guyd@myjabber.net This e-mail is private and may be confidential and is for the intended recipient only. If misdirected, please notify us by telephone and confirm that it has been deleted from your system and any copies destroyed. If you are not the intended recipient you are strictly prohibited from using, printing, copying, distributing or disseminating this e-mail or any information contained in it. We use reasonable endeavors to virus scan all e-mails leaving the Company but no warranty is given that this e-mail and any attachments are virus free. You should undertake your own virus checking. The right to monitor e-mail communications through our network is reserved by us.