What is VLSM in Networking?
VLSM stands for Variable Length Subnet Masking. It is a subnet design strategy that allows subnet masks to have variable sizes within the same network. In other words, it involves a process of subnetting a subnet.
VLSM enables network engineers to divide an IP address into different sized subnets and allocate it according to the network needs. This means that more than one mask is used for different subnets of a single class A, B, or C networks, thereby increasing the usability of subnets. The network administrator must use the relevant supporting routing protocol to use VLSM such as Intermediate System-to-Intermediate System (IS-IS), Routing Information Protocol v2 (RIPv2), Border Gateway Protocol (BGP), and Open Shortest Path First (OSPF).
