How can I test to see if my server is under a NAT configuration?

Introduction

With cPanel, we have some internal tools that can detect if the network configuration is set as a standard network configuration with a dedicated IP address or if it is a 1:1 NAT configuration.

Procedure

Generally, your hosting provider or data center will let you know both the internal and public IP addresses that your server may be using. If they do not, you can use this script with cPanel to test the routing of the network and see if it is a NAT configuration:

 /scripts/build_cpnat

If the system is not under a NAT configuration, then the script will give an output similar to this:

 info [build_cpnat] All publicly routeable addresses are the same as the local address. Not a NAT system.