How to access your Ubuntu server from external IP address

How to access your Ubuntu server from public IP address

This tutorial covered the resolution of below mentioned questions....

1. How to access your Ubuntu server from external/public IP address?
2. What setting to be changed to make a local server (Ubuntu) accessible over internet using external IP Address?
3. Where to change the settings?

Step 1: Login to your router using username and password.
Step 2: Goto Advance settings, then select NAT configuration.
Step 3: Select DMZ Host and configure the Ubunut server address as DMZ Host. To find the server address, execute "ifconfig" command on terminal.
Step 4: Now try to access your Ubuntu server from another network using external/public IP address. To find the external/public IP address
        execute "curl ifconfig.me" command on terminal.