I have an Ubuntu 11.04. I wanted to play around with iptables rules. But I don't see it installed. When I did:
sudo iptables -t nat -F chain
This is what it returned:
iptables v1.4.10: can't initialize iptables table `-nat': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded.
So is nat table not available?