What's wrong with this iptable rule?

Posted by warl0ck on Server Fault See other posts from Server Fault or by warl0ck
Published on 2012-11-18T05:51:18Z Indexed on 2012/11/18 11:09 UTC
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linux

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iptables

I run dnsmasq locally as a cache server, in the old days, I allow all INPUT packets from lo+, and set policy of INPUT to DROP:

-A INPUT -i lo+ -j ACCEPT

Now I decide to put this on the raw table to speed up rules matching,

-A PREROUTING -i lo+ -j ACCEPT

But that doesn't work as expected. Why? Since the packets get processed by the raw table first, then nat, then filter, why isn't that rule work the same as the old one?

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