Persistent BGP peer flapping - do you care?

Vincent Gillet vgi at
Sat Jan 19 14:57:22 UTC 2002

> 1) Do any of the ISPs see the persistent bgp peer flapping now?

Almost every day on different EBGP sessions (very few IBGP)
Reasons are most of the time circuit problems or max prefixes.
Most of the time, problem is not in BGP protocol itself.

>    The solution is to have an exponential backoff in
>    the rate of sending the Opens.

According to my records (i log BGP flaps for 6 months),
Exponential backoff on all boxes would reduce flaps by 80%.

>    If you have seen this, how many routers did this persistent
>    bgp peer flapping impact?  (Can you give a % of your routers or a
>    total number)?   How often does this impact your routers?

Almost 50% routers experience BGP flap in 6 months,
but 80% flaps are on 5% of all the boxes.

I can give you more precise data privatly is necessary :-)

> 2) Is this feature on in your machine by default?
>    If not, do you configure the exponential rates?

Most boxes i operate do not provide this feature.
Other have a constant timer before going from Idle to Active.

>  3)Do you track if your routers are in this state?
>    How do you track if your routers are in this state?

Noway to track for the moment.


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