# internal interface is ce0 at 192.168.1.1
# external interface is ce1 IP obtained via DHCP
# block all packets and allow specific services
*** NAT ***
*** POOLS ***


# Short packets which are fragmented too short to be real.
block in log quick all with short


# By default, block and log everything.
block in log on ce0 all
block in log on ce1 all
block out log on ce0 all
block out log on ce1 all


# Packets going in/out of network interfaces that aren't on the loopback
# interface should not exist.
block in log quick on ce0 from 127.0.0.0/8 to any
block in log quick on ce0 from any to 127.0.0.0/8
block in log quick on ce1 from 127.0.0.0/8 to any
block in log quick on ce1 from any to 127.0.0.0/8


# Deny reserved addresses.
block in quick on ce1 from 10.0.0.0/8 to any
block in quick on ce1 from 172.16.0.0/12 to any
block in log quick on ce1 from 192.168.1.0/24 to any
block in quick on ce1 from 192.168.0.0/16 to any


# Allow internal traffic
pass in quick on ce0 from 192.168.1.0/24 to 192.168.1.0/24
pass out quick on ce0 from 192.168.1.0/24 to 192.168.1.0/24


# Allow outgoing DNS requests from our servers on .1, .2, and .3
pass out quick on ce1 proto tcp/udp from ce1/32 to any port = domain keep state
pass in quick on ce0 proto tcp/udp from 192.168.1.2 to any port = domain keep state
pass in quick on ce0 proto tcp/udp from 192.168.1.3 to any port = domain keep state


# Allow NTP from any internal hosts to any external NTP server.
pass in quick on ce0 proto udp from 192.168.1.0/24 to any port = 123 keep state
pass out quick on ce1 proto udp from any to any port = 123 keep state


# Allow incoming mail
pass in quick on ce1 proto tcp from any to ce1/32 port = smtp keep state
pass in quick on ce1 proto tcp from any to ce1/32 port = smtp keep state
pass out quick on ce1 proto tcp from 192.168.1.0/24 to any port = smtp keep state


# Allow outgoing connections: SSH, WWW, NNTP, mail, whois
pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = 22 keep state
pass out quick on ce1 proto tcp from 192.168.1.0/24 to any port = 22 keep state

pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = 80 keep state
pass out quick on ce1 proto tcp from 192.168.1.0/24 to any port = 80 keep state
pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = 443 keep state
pass out quick on ce1 proto tcp from 192.168.1.0/24 to any port = 443 keep state

pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = nntp keep state
block in quick on ce1 proto tcp from any to any port = nntp keep state
pass out quick on ce1 proto tcp from 192.168.1.0/24 to any port = nntp keep state

pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = smtp keep state

pass in quick on ce0 proto tcp from 192.168.1.0/24 to any port = whois keep state
pass out quick on ce1 proto tcp from any to any port = whois keep state


# Allow ssh from offsite
pass in quick on ce1 proto tcp from any to ce1/32 port = 22 keep state


# Allow ping out
pass in quick on ce0 proto icmp all keep state
pass out quick on ce1 proto icmp all keep state


# allow auth out
pass out quick on ce1 proto tcp from ce1/32 to any port = 113 keep state
pass out quick on ce1 proto tcp from ce1/32 port = 113 to any keep state


# return rst for incoming auth
block return-rst in quick on ce1 proto tcp from any to any port = 113 flags S/SA


# log and return reset for any TCP packets with S/SA
block return-rst in log on ce1 proto tcp from any to any flags S/SA


# return ICMP error packets for invalid UDP packets
block return-icmp(net-unr) in proto udp all