IP Subnets and Network Masks
Subnet masks are used to specify the number of bits used to define a subnet
Subnet masks use the same format and representation techniques as IP addresses (e.g. 255.255.255.0)
Subnet masks have 1’s in the netid and subnet fields, and 0’s in the hostid field
Class B Subnetting example:
- Before Subnetting: [10:netid:hostid];
- After Subnetting: [10:netid:subnet:hostid];