BGP convergence problem

Andy B. globichen at
Tue Jun 8 14:27:16 UTC 2010

I finally decided to shut down all peerings and brought them back one by one.

Everything is stable again, but I don't like the way I had to deal
with it since it will most likely happen again when DECIX or an other
IX we're at is having issues.

I've seen a few BGP convergence discussions on NANOG, but none about
deadlock situations and what could be done to avoid them. Setting
higher MTU or bigger hold queues did not help.

- Andy

On Tue, Jun 8, 2010 at 2:35 PM, Ingo Flaschberger <if at> wrote:
> Dear Andy
>> This morning there was an ethernet loop problem on DECIX, causing many
>> BGP sessions to flap throughout the entire platform.
>> While this can happen, I am myself facing with BGP convergence
>> problems on our DECIX router (SUP720-3BXL with IOS SXI3).
>> De DECIX loop has been solved two hours ago, but my BGP sessions are
>> still flapping and not converging at all. This has been flooding our
>> logs, and is still going on:
> route half or more of the peering-network to Null -> lowering bgp session
> up's.
> (at the other side, your bgp-router seems to be overloaded).
> Kind regards,
>        Ingo Flaschberger

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