Dear experts,

I have some confusions over the use of iptables.

can u explain the order of processes of iptables?

Example, i have added rules to INPUT, OUTPUT, FORWARD, POSTROUTING, PREROUTING chains. In what order does iptables process rules in these chains ?


Thanks,

As far as the overall flow of packets through netfilter/iptables checkout this guide:

http://www.faqs.org/docs/iptables/tr...goftables.html

As far as the ordering of rule in the chain: The rules will be processed from top to bottom of each chain (you can view the order of rules in a chain with iptables -L or iptables -t nat -L). Keep in mind though that a packet does not have to pass through every chain and will do so in different orders depending on the flow of traffic (local packets will pass through a different chain order than will packets being forwarded through the system).