North American Network Operators Group

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Re: BGP route flap damping

  • From: Patrick W. Gilmore
  • Date: Mon Jan 16 08:20:42 2006

On Jan 16, 2006, at 7:28 AM, Gustavo Rodrigues Ramos wrote:

Last week we received a DoS attack which got down my BGP connections to
my upstream providers (for three or four times I believe). I also belive
that event caused some routers to suppress my BGP announcement.

I would appreciate suggestions on "how to proceed?" with this situation.
Remind everyone that flap dampening is no longer a good idea, and is in fact considered harmful. (Queue discussion at last RIPE.)

The problem is probably not flapping 3 times, but the amplification some people saw. (One of the reasons it was decided not to promote flap dampening at RIPE.)

Not much you can do about this in general. In your specific case, since we don't know why your sessions died, we don't know what to suggest to stop it. Perhaps change the timers with your upstream?

--
TTFN,
patrick