Multiple choice technology

Which of the following does not support VLSM?

  1. IGRP

  2. RIP V1

  3. OSPF

  4. EIGRP
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

RIP version 1 is a classful routing protocol that does not support VLSM (Variable Length Subnet Masking) or CIDR. IGRP, OSPF, and EIGRP all support VLSM. RIP v2 added VLSM support.

AI explanation

To answer this question, you need to understand what VLSM (Variable Length Subnet Masking) is and which routing protocols support it.

VLSM allows you to use different subnet masks within a network, which means you can allocate different numbers of IP addresses to different subnets. This allows for efficient use of IP addresses and better network scalability.

Let's go through each option to understand which one does not support VLSM:

Option A) IGRP - IGRP (Interior Gateway Routing Protocol) is a Cisco proprietary routing protocol that supports VLSM. Therefore, this option is incorrect.

Option B) RIP V1 - RIP (Routing Information Protocol) version 1 does not support VLSM. RIP v1 uses classful routing, which means it does not send subnet mask information in its routing updates. Therefore, this option is correct.

Option C) OSPF - OSPF (Open Shortest Path First) is a link-state routing protocol that supports VLSM. OSPF sends subnet mask information in its routing updates, allowing for the use of different subnet masks within a network. Therefore, this option is incorrect.

Option D) EIGRP - EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco proprietary routing protocol that supports VLSM. Therefore, this option is incorrect.

The correct answer is B) RIP V1. This option is correct because RIP v1 does not support VLSM, unlike the other options.

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