You're right, silly me. --vadim Forrest W. Christian <forrestc@iMach.com> wrote: On Mon, 13 Apr 1998, Vadim Antonov wrote:

Uh. Just modify BGP routes from that feed to have a next hop pointing to a black hole. route-maps are sometimes useful.

Could someone PLEASE explain to me how this is accomplished? Let's assume that you do use a route-map to set next hop to a null interface or a black hole or something for a prefix. AND set local pref appropriately so that route gets preferred. You now have a routing entry which essentially says: "forward packets DESTINED FOR the evil network to the black hole". What you really want is a routing entry which says: "forward packets FROM the evil network to the black hole". Now, if someone could enlighten me to a way which you can get BGP to make a routing/filter entry to do this second one, I'd be most grateful. BTW, I know you can do this with PERL or config scripts or whatever. The point is that I don't think that a RBL-like blackhole feed will fix a smurf attack from the "attacked" perspective, unless I have missed some knob somewhere. - Forrest W. Christian (forrestc@imach.com)