Question

what is the primary purpose of using variable length subnet masks (vlsm)?

a to decrease the complexity of network design
b to simplify the information internet routers need to locate ip networks
c to maximize address space usage within a private network
d to increase the ipv4 address space

Explanation:

Define VLSM and its primary function

Variable Length Subnet Masking (VLSM) allows a network administrator to use multiple subnet masks within the same IP address space. This enables subnets of different sizes to be created based on the specific host requirements of each subnet.

Evaluate the given options

• A is incorrect because VLSM actually increases network design complexity by requiring careful planning of overlapping subnets.
• B is incorrect because route summarization (CIDR), not VLSM, is primarily used to simplify routing tables for Internet routers.
• C is correct because VLSM prevents address waste by tailoring subnet sizes to the actual number of hosts needed, thereby maximizing address space efficiency.
• D is incorrect because VLSM cannot increase the total physical IPv4 address space, which is fixed at \(2^{32}\) addresses.

Answer:

• (A) To decrease the complexity of network design
• (B) To simplify the information Internet routers need to locate IP networks
• (C) To maximize address space usage within a private network (Correct answer)
• (D) To increase the IPv4 address space