Not really bitcoin specific but i'm sure there are lots of people running bitcoin on linux boxes and want to run a tight ship in regards to security.
So I have put together a firewall monitoring web based script running on PHP, requires ulog2, mysql (at the moment) its pretty straight forward.
I found there is a distinct lack of decent monitoring tools, especially anything updated in the last few years.
Anyway, check it out if your interested.. it's still pretty Alpha at the moment..
https://github.com/slothbag/fwlogviewIf you want to see it improved, send a small donation