[Day 4] 4. Subnet Mask

Fixed Length Subnet Mask (FLSM)

• Definition: In FLSM, the subnet mask is the same for all subnets within a network.
• Usage: This approach is simple and easy to manage but can lead to inefficient use of IP addresses.
• Example: If you have a network with a subnet mask of 255.255.255.0, all subnets will have this same mask, regardless of their size or number of hosts.

Variable Length Subnet Mask (VLSM)

• Definition: VLSM allows for different subnet masks within the same network, providing more efficient use of IP addresses.
• Usage: This method is more flexible and can accommodate networks of varying sizes more efficiently.
• Example: In a network, one subnet might have a subnet mask of 255.255.255.0, while another might have a mask of 255.255.254.0, allowing for different sizes of subnets based on the number of hosts needed.

VLSM is particularly useful in hierarchical network designs, where different subnets may have different requirements for the number of IP addresses.