IPTables Firewall Commands
These options specify the specific action to perform. Only one of them can be specified on the command line unless otherwise specified below. For all the long versions of the command and option names, you need to use only enough letters to ensure that iptables can differentiate it from all other options.
Append one or more rules to the end of the selected chain.
Delete one or more rules from the selected chain.
Insert one or more rules in the selected chain as the given rule number.
Replace a rule in the selected chain.
List all rules in the selected chain.
Flush the selected chain.
Zero the packet and byte counters in all chains.
Create a new user-defined chain by the given name.
Delete the optional user-defined chain specified.
Set the policy for the chain to the given target.
Rename the user specified chain to the user supplied name.
(Help) Give a (currently very brief) description of the command syntax.