2 # block all ICMP packets.
4 block in proto icmp all
6 # allow in ICMP echos and echo-replies.
8 pass in on le1 proto icmp from any to any icmp-type echo
9 pass in on le1 proto icmp from any to any icmp-type echorep
11 # block all ICMP destination unreachable packets which are port-unreachables
13 block in on le1 proto icmp from any to any icmp-type unreach code 3