http://www.debian-administration.org/articles/187

Using iptables to rate-limit incoming connections
Posted by Steve on Sun 17 Jul 2005 at 00:39

Tags: firewalls, iptables, ssh
The iptables firewall has several useful extension modules which can be used to in addition to the basic firewall functionality. One of the more interesting of these extensions is the "recent" module which allows you to match recent connections, and perform simple throttling on incoming connections.




iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent \
--set

iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent \
--update --seconds 60 --hitcount 4 -j DROP

--
map{ map{tr|10|# |;print} split//,sprintf"%.8b\n",$_}
unpack'C*',unpack'u*',"5`#8<3'X`'#8^-@`<-CPP`#8V/C8`"