Q1. Which of the following is true about VLSM?
A. VLSM allows route summarization
B. VLSM makes less efficient use of IP addresses compared to fixed subnet mask addressing
C. VLSM can be implemented on both link state and distance vector routing protocols.
D. VLSM is a Cisco proprietary technology
Correct Answer: A
VLSM (Variable Length Subnet Masking) allows efficient use of IP addresses. Networks implemented with VLSM can be summarized more efficiently due to manual control. With a distance vector protocol such as RIP or IGRP, only one subnet mask value can be used on a network, as subnet mask values are not sent in routing updates.