What is the purpose of Variable Length Subnet Masking (VLSM)?

The purpose of Variable Length Subnet Masking (VLSM) is to allow subnetting of varying sizes within the same network. VLSM enables network administrators to create subnets that have different subnet masks, accommodating networks of different sizes based on specific needs. This flexibility allows for the efficient use of IP address space, providing the ability to allocate more addresses to subnets that need them, while assigning fewer addresses to smaller subnets.

For instance, if a certain segment of a network requires a larger number of hosts, a subnet with a longer mask can be created to accommodate that demand. Conversely, smaller segments can utilize shorter masks, reducing waste in IP address allocation. This capability enhances the overall efficiency of IP address utilization compared to a traditional fixed-length subnet masking method, which limits all subnets to the same size regardless of actual need.

The other choices do not accurately reflect the primary purpose of VLSM. Restricting network access is a function related to security measures rather than subnetting. Simplifying IP address configuration and eliminating the need for routing tables do not directly relate to the essence of what VLSM achieves.