# # log all inbound packet on le0 which has IP options present # log in on le0 from any to any with ipopts # # block any inbound packets on le0 which are fragmented and "too short" to # do any meaningful comparison on. This actually only applies to TCP # packets which can be missing the flags/ports (depending on which part # of the fragment you see). # block in log quick on le0 from any to any with short frag # # log all inbound TCP packets with the SYN flag (only) set # (NOTE: if it were an inbound TCP packet with the SYN flag set and it # had IP options present, this rule and the above would cause it # to be logged twice). # log in on le0 proto tcp from any to any flags S/SA # # block and log any inbound ICMP unreachables # block in log on le0 proto icmp from any to any icmp-type unreach # # block and log any inbound UDP packets on le0 which are going to port 2049 # (the NFS port). # block in log on le0 proto udp from any to any port = 2049 # # quickly allow any packets to/from a particular pair of hosts # pass in quick from any to 10.1.3.2/32 pass in quick from any to 10.1.0.13/32 pass in quick from 10.1.3.2/32 to any pass in quick from 10.1.0.13/32 to any # # block (and stop matching) any packet with IP options present. # block in quick on le0 from any to any with ipopts # # allow any packet through # pass in from any to any # # block any inbound UDP packets destined for these subnets. # block in on le0 proto udp from any to 10.1.3.0/24 block in on le0 proto udp from any to 10.1.1.0/24 block in on le0 proto udp from any to 10.1.2.0/24 # # block any inbound TCP packets with only the SYN flag set that are # destined for these subnets. # block in on le0 proto tcp from any to 10.1.3.0/24 flags S/SA block in on le0 proto tcp from any to 10.1.2.0/24 flags S/SA block in on le0 proto tcp from any to 10.1.1.0/24 flags S/SA # # block any inbound ICMP packets destined for these subnets. # block in on le0 proto icmp from any to 10.1.3.0/24 block in on le0 proto icmp from any to 10.1.1.0/24 block in on le0 proto icmp from any to 10.1.2.0/24