Hi,
I am working on a patch for iptables.c to prohibit inserting the same rule twice. Inserting same rule twice does not cause any problems but also is not meaningful.

After the patch iptables will has an option to force the system to insert the rule twice but by default it will check whether the rule is already inserted or not and will give warning.

I think that checking the rule in the system may take too much time for systems with thousands of rules, so an option argument will be a good choice.

I wonder why this has not been done before. Please write your suggestions and thoughts.

thanks,

-- 
Ozgur Akan