Subnet Mask

• Subnet Mask is a 32-bit number masks an IP address, and divides the IP address in to "network address" and "host address"(<network><host>).
• Subnetting further divides the host part of an IP address in to subnet and host address(<network><subnet><host>).
• Subnet mask is made by setting network bits to all "1"s and setting all host bits to "0"s.





• In a network two host addresses "0",255" are reserved for special purpose and cannot be assigned to hosts.
• The "0" address is assigned to a network address and "255" address is assigned to a broadcast address.
• IPV4 Classes with Default Subnet Mask.





• Subnetting of an IP addrerss.





• Finding Subnetwork address.

Examples: