What is Subnet Mask, Types of Subnet Mask? Why you should care? Well, every device in the IPv4 network has its own subnet mask, that defines which subnet device it belongs to. Subnet mask is a 32-bit number that is being combined with device IP for identification of its subnetwork.
Subnet mask can be written either in binary (111111.111111.111111.000000) or decimal (255.255.255.0) form. Subnet masks are assigned through the automatic service like DHCP or manually by the network administrator.
Subnetting is necessary for dividing parts of the network into smaller logical networks for easier management, It helps to take care and assign limited number of IPs, and control and separate network traffic.
The subnet masks differ depending on the way the subnet is masked. If the subnet mask is not defined or is unnecessary, then it is being assigned default value. List of default subnet mask values is shown in Table 1.
