Can iptables or other firewall solutions can do this for me?

[Rob Sterenborg]

netfilter-bounces at lists.netfilter.org <> wrote:
> Let me tell the background first...
> 
> We have a web server, recently received a lot of requests from oversea
> proxy. The requests are to spam our applications (i.e. leave
> comments). They don't success, since they never get the correct
> captacha. 
> 
> But the problem is: They are doing requests & requests forever (even
> with no success). This lead to:
> 
> 1. Waste of CPU time of our web server
> 2. Waste of oversea bandwidth
> 
> 
> Can iptables or related tools or packages can do this for me?
> 
> p.s. Since they are changing proxy all the time, so might be need a
> automatic solutions, 

Not directly, but this would be a solution I would think of:

You could modify the comment-script so that it logs the IP from the
hosts that attempt to leave a comment but fail doing so (if the script
doesn't do this already).
After that you can write a script that parses and clears the logfile
every x minutes to filter the largest offenders. You can enter these
offending IP's in a user defined blocking-chain which is called in the
INPUT chain (or FORWARD chain, depending on your setup) to block further
requests from these IP's.


Grts,
Rob