/sbin/ipchains - F forward
/sbin/ipchains - F input
/sbin/ipchains - F output
/sbin/ipchains - P forward DENY
/sbin/ipchains - P input ACCEPT
/sbin/ipchains - P output ACCEPT
external_interface=192.168.1.1
/sbin/ipchains - A input - j ACCEPT - i lo
/sbin/ipchains - A output - j ACCEPT - i lo
/sbin/ipchains - A input - j DENY - i eth0 - s 192.168.1.0/24
/sbin/ipchains - A input - j DENY - i eth0 - d 192.168.1.0/24
/sbin/ipchains - A output - j DENY - i eth0 - s 192.168.1.0/24
/sbin/ipchains - A output - j DENY - i eth0 - d 192.168.1.0/24
/sbin/ipchains - A input - j DENY - i eth1 - s 255.255.255.255
/sbin/ipchains - A input - j DENY - i eth1 - d 0.0.0.0
/sbin/ipchains - A input - j DENY - i eth1 - s 240.0.0.0/3
/sbin/ipchains - A forward - j ACCEPT - i eth0 - s 192.168.1.0/24
/sbin/ipchains - A forward - j ACCEPT - i eth0 - d 192.168.1.0/24