[CentOS] Simple IPTABLES Question

[Kenneth Porter]

--On Tuesday, August 19, 2008 10:15 AM -0500 David Dyer-Bennet 
<dd-b at dd-b.net> wrote:

> That's the right general approach; duplicate the drop rule but with a LOG
> target and appropriate logging parameters.

Another approach is to create a subchain that just logs and drops (no match 
rules), and in your main chain you match on the desired packet and jump to 
the subchain. That eliminates the need to maintain the same match in two 
places, and reduces the number of rules a non-dropped packet has to pass 
through.