MrKiwi wrote:
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.
There is an expires ipfilter module, not a standard part of the kernel, but available from netfilter.org. I wish it were standard, there's a lot of folk I would cheerfully banish for a few hours: you trigger a spam alert, I block your /24 for 24 hours. You ping my ftp port, I take out your /24 for a day.