Last time here I have given you a few links to check out and learn something more about iptables. If you start learning iptables at the very start of your VPS hosting life your life will be easier later on And if you are an administrator and owner of the web sites in one person [...]

I think that the majority of Linux distro you could come across these days will be equipped with a 2.6 or later Linux kernel and thus iptables should be included by default. Older kernels do have a firewall solution as well, but it is called by a different name and I will not cover it [...]