icmp rpf

Wed Sep 27 23:04:37 UTC 2006

Possible approach for small.net - ok, you know that big.net will drop
any packets sourced from x.x.x.x if there's no route there (loose uRPF
for downstream ISPs like small.net, strict uRPF for end-users.)  So
give them a route.  Either give them a route on one of your direct
interfaces to them, and then get rid of the packets by ACL or by
null-routing it, or if that causes too much trouble, get yourself a
56kbps line from a spare router and advertise it from there.