Knowledgebase
CSF xt_connlimit...FAILED
My CSF firewall says "xt_connlimit...FAILED" - please add xt_connlimit module.
Actually there is connlimit module and it is enabled. However the kernel implementation for connlimit has changed through the years. Distributions which by default run on 2.6.32 kernel (i.e. Debian 6 or CentOS 6) are incompatible with the xconnlimit implementation in the 2.6.18 OpenVZ kernel, which we use for it's stability.
A workaround would be to use CentOS 5 - CSF reports no problem with using the connlimit feature with CentOS 5.
If you want to use debian 6 64bit, you can do the following:
apt-get -y remove iptables
wget http://archive.debian.org/debian/pool/main/i/iptables/iptables_1.3.6.0debian1-5_amd64.deb
dpkg -i ./iptables_1.3.6.0debian1-5_amd64.deb
After that CSF should no longer report erros. Whether it really works - you have to test :)