netfilter

To create and save iptables rules the default Debian way, this is the way to go:

• create your rules using the CLI [1] iptables
• save them on the active rule by issuing a /etc/init.d/iptables save active
• create the rules for the inactive state (when booting, for example) and save them accordingly

That way, the rules will survive a reboot. To delete a specific rule previously saved as above:

• go into /var/lib/iptables/active and take the

To communicate using a tool like Microsoft NetMeeting or GnomeMeeting through a Linux (kernel 2.4.x-based) firewall, you have to redirect some ports to one IP address in the inside network, otherwise, it won't work. Here is a little script meant to achieve exactly that:

#!/bin/sh
# Script to redirect H.323 trafic to one specific IP behind the firewall

IPTABLES=/sbin/iptables
OUT_DEV=ppp0
IN_HOST=192.168.11.33
TCP_PORT_RANGE=30000:30010
UDP_PORT_RANGE=5000:5003
TCP_LISTENING_PORT=1720

#$IPTABLES -