Iptables provides packet filtering, network address translation (NAT) and other packet mangling.

Two of the most common uses of iptables is to provide firewall support and NAT.

List all the rules in effect (by default, none):

 # iptables --list

 Chain INPUT (policy ACCEPT)
 target     prot opt source               destination

 Chain FORWARD (policy ACCEPT)
 target     prot opt source               destination

 Chain OUTPUT (policy ACCEPT)
 target     prot opt source               destination


Configuring iptables manually is challenging for the uninitiated. Fortunately, there are many configuration tools (wizards) available to assist: e.g., fwbuilder, bastille, ferm.

Manual configuration:

More to come... this is just a start since I noticed there wasn't much info on iptables.


Resources: