[CentOS] This firewall rule will self-destruct
mrkiwi at gmail.com
Sat Mar 17 03:39:38 UTC 2007
Benjamin Smith wrote:
> On Friday 16 March 2007, MrKiwi wrote:
>> mitigate a situation
>> where you have no control over an intermediate firewall that
>> only passes port 80
> Yes, that's EXACTLY what I'm trying to do... but I dont' see how this exactly
> relates to port knocking.
> Port knocking seems to be that you log connection attempts to various ports
> that are otherwise closed, EG:
> iptables -I input -p tcp -j DENY -l
> and then watch the log file for a specific, exact sequence of connections from
> a common source IP. How would that help me here?
Yes - you're right, it would not be a simple drop in
solution. In the other scenario i suggested (reducing your
visibility) port knocking would have been perfect.
You could still use a modified port knocking system i think
- just using a url hit to do the triggering instead of a
port knock sequence. That way the port knock config takes
care of removing the iptables line after x seconds.
See Michael Rash's pdf
His implementation is rock solid, and easy to config. Also
anyone with some grep and script skills should be able to
hack the port-knock -> httpd-log-watcher part you need.
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