How to make a local computer with local IP visible to Internet

There are two types of IPs, one is Private IP range and other is Public IP range.

Private and Public IP Addresses Explained

Public and Private Addresses

How to Find Your Computer’s Private & Public IP Addresses

 As you are aware, the Private IP (eg. home network or private network) is not visible or accessable from other computer in the public network (eg. internet).

This limitations of Private IP can be overcome by using a feature (in the router or modem + router) called DMZ or DeMilitarized Zone. Using this feature one Private IP can be made visible to the public network. The advantage of making a local computer with Private IP to public is that the we can make use of many programs that usually work on Public IP. For example Web Server, File Server, server for remote access (SSH server), Security systems which uses internet etc.

Let us configure DMZ in a BSNL ADSL Modem + Router.

We cannot check whether the configuration works as expected using the computer that comes under the same ADSL Modem + Router. To check we require a computer having different Public IP.  That is, a computer having internet connection with another modem.

Start a web browser. In the address bar type the Public IP. If we are using the computer which comes under the same public IP, it will show the modem configuration page (see the first image).

If we are using a computer with different internet connection it will show the program (eg Web Server, File Server etc) which works in the local computer with local IP.