limit number of connections for a single ip on port 80 to CentOS 5.5
 

How to number of connections for a single ip on port 80 to CentOS 5.5 with iptables?
connlimit did not work on CentOS and nginx does not provide a module for that

iptables -I INPUT -p tcp -s 0/0 –sport 513:65535 –dport 80 -m state –state NEW,ESTABLISHED -m recent –set -j ACCEPT
iptables -I INPUT -p tcp –dport 80 -m state –state NEW -m recent –update –seconds 2 –hitcount 25 -j DROP
iptables -A OUTPUT -p tcp -s 0/0 -d 0/0 –sport 22 –dport 513:65535 -m state –state ESTABLISHED -j ACCEPT

that rules should do what you want, works fine for me.

Thanks nullbyte!
why do you add –sport 513:65535 ?

from 3 lines your required line is
iptables -I INPUT -p tcp –dport 80 -m state –state NEW -m recent –update –seconds 2 –hitcount 25 -j DROP

The third one is for ssh access.

Destination port 513-65535 from a source port of 22