Maybe I read your question wrong, but null-routing things at your border is often not very useful if the traffic is flooding your transit links. Most transits publish their community lists - you just need to tag the prefix you want to blackhole with the right community.
See example from HE: http://www.he.net/adm/blackhole.html <http://www.he.net/adm/blackhole.html>-Jack Carrozzo On Tue, Feb 22, 2011 at 4:42 PM, David Hubbard < dhubb...@dino.hostasaurus.com> wrote: > I was wondering if anyone has a howto floating around on the > step by step setup of having an internal bgp peer for sending > quick updates to border routers to null route sources of > undesirable traffic? I've seen it discussed on nanog from > time to time, typically suggesting using Zebra, but could > not search up a link on a step by step. > > Thanks, > > David > >