or forge the source ip on the neighbors /30 or /31 (why aren't you using
/31s anyway) and call it done.
provided your gear supports it an acl (this is one reason layered acls
would be nice on routers) per peer with:
permit /30 eq 179 /30
permit /30 /30 eq 179
deny all-network-gear-ip-space (some folks call it backbone ip space, Paul
Quinn at cisco says: "Infrastructure ip space")
no more traffic to the peer except BGP from the peer /30. No more ping, no
more traceroute of interface... (downsides perhaps?) and the 'customer'
can still DoS himself :( (or his compromised machine can DoS him)