Miscellaneous notes on IPTables.
The positions are called "chains":
|filter||INPUT FORWARD OUTPUT|
|nat||PREROUTING POSTROUTING OUTPUT|
|mangle||PREROUTING INPUT FORWARD OUTPUT POSTROUTING|
A chain is a list of rules. Each rule has a condition and an action:
When a packet enters a chain, it is tested against each rule in turn. The action of a rule is carried out if the condition is met. Some actions cause the packet to leave the chain immediately, skipping untested rules. The actions are called TARGETS. Some popular targets are:
When you configure your firewall, you build this list of rules using the iptables tool.
The state diagram looks like this (using the GraphViz? plugin) :-
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lib/main.php:839: Notice: PageInfo: Unknown action
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