Example Packet Filtering Rules:

• Protect 128.105.0.0 network with OpenBSD pf: block in log all block in log quick on $campus_if from 128.105.0.0/16 to any pass in quick on $campus_if proto tcp from any to 128.105.1.1/32 port = 25 ... pass in quick on $cs_if proto tcp from 128.105.0.0/16 to any keep state