What Is My IP Subnet Mask?

Knowing your IP subnet mask allows you to hide the network portion of your computer identity. It also allows you to create multiple sub-networks from the primary network IP address.

IP subnet masks tell a network how to direct traffic.


The IP subnet mask works with the IP address to split network traffic into manageable groups. Using these groups alleviates congestion within the network.


A host address and a network address make up an IP address. The subnet mask of the identifies to which part of the IP address a subnet belongs.


Click on the 'Start' button, then click on "Run." Type "cmd" into the "Run" box and press "Enter." A command prompt will open. Type "IPCONFIG" into the command prompt. Your subnet mask will display next to "subnet mask" in the list.