[luau] Port Knocking

[MonMotha]

Taylor Cody L Contractor 502 AOS/PETS wrote:
> I thought this was a good article.  Port knocking sounds like a neat and
> simple solution to shut down as many ports as possible when they are not in
> use.  At least for a small office or a home network.
> -Cody
> 
> An introduction to how trusted users can manipulate firewall rules to
> transmit information across closed ports.
> http://www.linuxjournal.com/article.php?sid=6811


I haven't tried it yet, but one could presumably do really cool, similar stuff 
entirely in kernel space with iptables and some various matches.

For example, the recent match combined with, say, a string match.  This could 
simplify setup by not requiring complex log monitoring daemons to see the 
"knock" and modify the ruleset to open ports.

--MonMotha