Whats my IP?

Have you ever wondered what your public IP is? Wait, what is a public IP?

An IP address is a number sequence of the form 123.123.123.123. Each 3 digit number sequence can be from 0 to 255. Valid examples are 2.100.32.12, 192.168.1.1, etc

Every device connected to the Internet has to have an IP address. Think of it like the address of your house. Every house needs a clear address by which it can be reached. Similarly all devices connected to the Internet need IP address to communicate with servers and other devices.

There is a one difference between a house address and IP address. Unlike house addresses which are unlimited, IP addresses are limited due to the format used. Hence it is required to optimally use the available IP address space.

Two common methods that are used to solve this problem are:
1) Dynamically assign IP addresses to devices only when they are connected to the Internet. Not all devices are connected always, hence by allocating dynamically in this form more devices can be supported
2) Use NATing – basically devices physically closer to each other (on a single network) are assigned local IP addresses and anther device (router) translates the local IP address to a common IP address. The router is responsible for adding addtional information in the outgoing data packets so that it can route response packet to the appropriate device.

To test this out, open your browser and navigate to whats my IP tool. In the edit box you will find your public IP address.

Now, open command prompt in your system (Start->Run->cmd.exe) and at the “c:>” prompt type “ipconfig /all”. If you see a different IP address then your network is using one of the above methods to optimize IP address space.