I've just setup my first Cisco router. It's an 837 ADSL router. I've got it up and running ok but I want to stop it replying to ICMP requests although I want to allow ICMP requests out. It's the first time I've touched a Cisco router although I'm aware that to set advanced settings you have to telnet into the router and use commands. I have managed to get into the privileged command sets but don't know the exact command I need to deny ICMP coming in. Any help would be greatly appreciated.