How to configure NAT with iptables on a VPS.

NAT ( network-address-translation ) with iptables  helps us in how to select the packets we want to mangle. We can easily configure NAT on a OpenVZ VPS by following the below steps.

Lets first consider a VPS in which NAT is not enabled. Trying to POSTROUTE from VPS throws you errors.

iptables -t nat -A POSTROUTING -s 10.9.0.0/24 -o venet0 -j SNAT –to 111.140.170.134

or iptables -t nat -nvL

iptables v1.3.5: can’t initialize iptables table `nat’: Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

To Enable NAT :

* Login to Node server.

Check vzcinfiguration file to find whether NAT is enabled or not.

grep -i iptables /etc/vz/vz.conf

You will get