Hi,
Assuming you want to stop people pinging you, use iptables (2.4 series kernels) / ipchains (2.2 series kernels) to drop the relevant packets. You just add some icmp rules something like the following :
/sbin/iptables -A INPUT -p icmp --icmp-type echo-requested -j DROP
/sbin/iptables -A OUTPUT -p icmp --icmp-type echo-reply -J DROP
or
ipchains -A input -p icmp -s any/0 8 -d any/0 -j DROP
ipchains -A output -p icmp -s any/0 0 -d any/0 -j DROP
(Type 8 icmp = Echo request; Type 0 = Echo reply)
Rgds, Iain