Syntax Comparison
PF

Equivalent PF config

set skip on $LO_IFACE
nat on egress inet from $LAN_IFACE:network to any -> (egress)
scrub in
block log
pass out inet
pass in on (egress) inet proto tcp from any to (self) port { 21, 22, 80, 113 }
pass in on (egress) inet proto icmp from any to (self) icmp-type echo-req
pass in on $LAN_IFACE inet from $LAN_IFACE:network modulate state