A submask is designed to separate the network id portion of an IP address from the host or client portion. This helps a router determine whether the packet needs to be forwarded to another network.
The subnet mask separates the network id from the client id in the IP address for a sender or receiver.
It does not require a subnet mask.
There is no technical term called "subnet mass number." It might be a misconstrued term. Subnetting is dividing a network into smaller subnetworks for better organization and security. Mass number is used in chemistry to denote the total number of protons and neutrons in an atom's nucleus.
If this is a default subnet mask, then it would be a class C subnet mask. If you are subnetting a network and this is not the default subnet mask, then it could be either a class A or class B.
The default subnet mask has a standard size. The custom subnet mask allows you to make subnets that are smaller or larger than the default.
255.255.255.0
2 given subnets
255.255.255.0
The default subnet mask would be 255.255.0.0 for a class B address.
if the ip address is 192.168.2.1 then the subnet mask should be 255.255.255.0
Subnet mask for the above is 255.0.0.0
By changing subnet mask..from 255.255.224.0 to 255.255.240.0 Number of subnetworks increase and the number of host in each subnetwork decreases