HELP i'm being ping flooded

[Laurent SEROR]

Hi,   I need to suppres icmp service because I'm being flood by ping by a hacker (about 3Mbits during all day). I can't install ipfwadm or ipchains because I got a cobalt on 2.0.34 and ipfwadm make an error on compilation.   Is there a simple way to stop all icmp ????   Thanx Laurent SEROR