In order to squeeze every drop of performance from my routers, I think I'd seen where a router can be told not to respond with ICMP Unreachable messages. People scanning our network from the Internet & other scanning behaviour for networks that we don't route, cause ICMP unreachables. How do I teach my router to simply drop the packet, and provide NO response back to the sender.
My routers interfaces are just two DS1, and a FastEthernet interface, both with MTUs of 1500 bytes, so there shouldn't be any pathMTU discovery issues with turning off the ICMP Unreachable messages.
-Alex
