# $OpenBSD: faq-example1,v 1.3 2005/07/02 16:16:39 joel Exp $ # # Firewall for Home or Small Office # http://www.openbsd.org/faq/pf/example1.html # # macros int_if = "fxp0" ext_if = "ep0" tcp_services = "{ 22, 113 }" icmp_types = "echoreq" priv_nets = "{ 127.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12, 10.0.0.0/8 }" comp3 = "192.168.0.3" # options set block-policy return set loginterface $ext_if # scrub scrub in all # nat/rdr nat on $ext_if from $int_if:network to any -> ($ext_if) rdr on $int_if proto tcp from any to any port 21 -> 127.0.0.1 \ port 8021 rdr on $ext_if proto tcp from any to any port 80 -> $comp3 # filter rules block all pass quick on lo0 all block drop in quick on $ext_if from $priv_nets to any block drop out quick on $ext_if from any to $priv_nets pass in on $ext_if inet proto tcp from any to ($ext_if) \ port $tcp_services flags S/SA keep state pass in on $ext_if proto tcp from any to $comp3 port 80 \ flags S/SA synproxy state pass in on $ext_if inet proto tcp from port 20 to ($ext_if) \ user proxy flags S/SA keep state pass in inet proto icmp all icmp-type $icmp_types keep state pass in on $int_if from $int_if:network to any keep state pass out on $int_if from any to $int_if:network keep state pass out on $ext_if proto tcp all modulate state flags S/SA pass out on $ext_if proto { udp, icmp } all keep state