An IP address is a 32-bit number that identifies a host on a network. Each device that wants to communicate with other devices on a TCP/IP network needs to have an IP address configured. For example, in order to access the Internet, your computer will need to have an IP address assigned (usually obtained by your router from the ISP).
An IP address is usually written in the form of four decimal numbers seperated by periods (e.g. 10.0.50.1). The first part of the address represents the network the device is on (e.g. 10.0.0.0), while the second part of the address identifies the host device (e.g. 10.0.50.1).
In contrast to MAC address, an IP address is a logical address. It can be configured manually or it can be obtained from a DHCP server.
Private IP addresses
There are three ranges of addresses that can be used in a private network (e.g. your home LAN). These addresses are not routable through the Internet.
Private addresses ranges are:
- 10.0.0.0 – 10.255.255.255
- 172.16.0.0 – 172.31.255.255
- 192.168.0.0 – 192.168.255.255
How to find out your IP address
If you are using Windows, start the Command Prompt (Start – Programs – Accessories – Command Prompt). Enter the ipconfig command. You should see a field called IP Address:
Linux users:
Enter ifconfig. You should see a field called inet addr:
