The firewallchain type is something that some people may never use. It allows you to manage the firewall chains themselves under iptables.

If you recall from the earlier section, the firewall rules are contained in chains. Firewall chains are groupings of related rules. By default, the filter table, which handles packet filtering, contains three chains INPUT, OUTPUT, and FORWARD. These chains filter packet input when they are forwarded and on output. There are other default chains present in other tables.

It is possible to add your own chain to better organize your firewall rules. You can then use the jump rule to send packets into your new chain.

You can use this type if you want to change some default parameters about a chain you created.

The parameters available to the firewall chain type are as follows: