[CentOS] Re: Email dictionary attacks and firewall

Wed Aug 16 20:06:55 UTC 2006
Randall Hobbs <randall at thereliantinnovationgroup.com>

-----Original Message-----
>>Better would be a rule to forward their connection to a honeypot / tarpit
box that would do what 
>>you want ... tie up their connection for a while.

You don't have to have it forward to a separate box for the tarpit to work.
Tarpit rules can be placed into the firewall so that any packets from a
particular host (or network) get tarpitted, while allowing everyone else's
to come through to the listening daemon. You just have to give it a specific
source and port. The following would tarpit port 25 (TCP) for the IP address
99.99.99.99, while allowing everyone else through to the listening SMTP
daemon:

iptables -I INPUT -s 99.99.99.99 -p tcp --dport 25 -j TARPIT

So it's just a matter of adding rules per each host that causes a problem.

--
Take care,
Randall


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