NetBSD-5.0.2/regress/sys/kern/ipf/regress/i7

pass in on ed0 proto tcp from localhost to localhost port = 23 flags S/SA
block in on lo0 proto tcp from any to any flags A
pass in on lo0 proto tcp from any to any flags /SAP
block in on lo0 proto tcp from any to any flags 0x80/A
pass in on lo0 proto tcp from any to any flags S/18
block in on lo0 proto tcp from any to any flags 2/18
pass in on lo0 proto tcp from any to any flags 2
block in on lo0 proto tcp from any to any flags /16
pass in on lo0 proto tcp from any to any flags 2/SA