Variable Length Subnet Masking (VLSM) requires all subnets within an IP network to use the exact same subnet mask length.

### Why this is right The material explicitly advises, “Try not to do this on a LAN.” Therefore, the claim that it recommends VLSM on every LAN reverses the stated guidance. ### The concept VLSM can conserve address space and support route summarization, but a technique's potential benefits do not mean it is recommended in every setting. A local area network (LAN) is a network serving a local site or area. The slide's guidance is specifically to avoid VLSM on a LAN where possible, while also noting that VLSM can ease administration and troubleshooting. Use the material's stated qualification rather than turning a possible benefit into a universal rule. ### The other options - **True**: this would fit a claim that the material recommends VLSM on every LAN, but it says the opposite. ### Terms - **VLSM**: Variable Length Subnet Masking. Subnetting with different mask lengths. - **LAN**: Local Area Network. A network serving a limited local area or site. ### Remember A stated benefit is not the same as a recommendation for every network.