GATE CS 2022 Set 1 — Question 22

MCQ+1 / -0.33MediumSubnetting & CIDRNetwork Layer: AddressingComputer Networks

Computer Networks → Network Layer: Addressing → Subnetting & CIDR

Last updated 5 September 2026

Question

Consider an enterprise network with two Ethernet segments, a web server and a firewall, connected via three routers as shown below. What is the number of subnets inside the enterprise network?

Correct answer (C) 6 Solution A subnet is required for each segment of the network that is not further subdivided. In a router-based network, each interface of a router connects to a different subnet. Let's identify the distinct network segments in the given diagram: 1. The link between the top router (connected to the Internet) and the firewall. This is a point-to-point link and requires one subnet. 2. The link between the firewall and the central router. This is another point-to-point link requiring one subnet. 3. The left Ethernet segment connected to the central router. This is a broadcast domain and requires one subnet. 4. The link between the central router and the web server. This is a point-to-point link requiring one subnet. 5. The link between the central router and the right router. This is a point-to-point link requiring one subnet. 6. The right Ethernet segment connected to the right router. This is another broadcast domain and requires one subnet. Counting these up, we have a total of 6 subnets inside the enterprise network. Therefore, the correct answer is 6. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

Review answer and solution without JavaScript

Interactive answer checking needs JavaScript. The published solution is available below.

Correct answer (C) 6 Solution A subnet is required for each segment of the network that is not further subdivided. In a router-based network, each interface of a router connects to a different subnet. Let's identify the distinct network segments in the given diagram: 1. The link between the top router (connected to the Internet) and the firewall. This is a point-to-point link and requires one subnet. 2. The link between the firewall and the central router. This is another point-to-point link requiring one subnet. 3. The left Ethernet segment connected to the central router. This is a broadcast domain and requires one subnet. 4. The link between the central router and the web server. This is a point-to-point link requiring one subnet. 5. The link between the central router and the right router. This is a point-to-point link requiring one subnet. 6. The right Ethernet segment connected to the right router. This is another broadcast domain and requires one subnet. Counting these up, we have a total of 6 subnets inside the enterprise network. Therefore, the correct answer is 6.

Continue learning with Success Tracker

Use Success Tracker to ask about the reasoning, then try another GATE CS question to check your understanding.

AI-powered practice· Unlimited practice on eligible plans

PYQs with solutions: Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
Practice that adapts: Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
AI doubt support: Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.

Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.

This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.