Computer Networks: notes and questions
For CSE/IT students
Notes for each topic, a formula sheet, practice questions and 52 past GATE questions from 10 papers (2018–2026), 52 of them solved step by step.
- previous-year questions
- 52previous-year questions
- solved step by step
- 52solved step by step
- GATE papers, 2018–2026
- 10GATE papers, 2018–2026
- topics with notes
- 7topics with notes
Foundation
Learn the subject one topic at a time. Each topic has notes, the key formulas and practice questions.
Topic notes and formulas
Notes on every topic, with the key formulas and practice.
Layering and switching: circuit, packet and virtual circuit
Layering splits network communication into a stack of layers, each with one job, its own header and its own unit of data; switching decides how data crosses the links between two hosts (a dedicated circuit, independent packets, or packets along a fixed virtual path).
5 practice questions
Performance metrics: delay, throughput and link utilisation
Performance metrics describe how long data takes to cross a network and how much of a link's capacity is actually used.
5 practice questions
Data link layer: error detection, medium access control and Ethernet
The data link layer moves frames reliably across one link or one shared network.
5 practice questions
Routing: distance vector and link state
Routing decides the path a packet should take; forwarding moves it one hop along that path.
5 practice questions
IPv4: addressing, CIDR, fragmentation and NAT
An IPv4 address is a 32-bit number split by a prefix length into a network part and a host part.
6 practice questions
TCP: flow control, congestion control and sockets
TCP gives a reliable, ordered byte stream between two sockets.
6 practice questions
Application layer: DNS and HTTP
DNS turns names into IP addresses through a hierarchy of servers and caches, and HTTP is the stateless request-response protocol that carries web pages.
5 practice questions
Computer Networks formulas by topic
GATE
Past GATE questions on Computer Networks by topic and year, the full papers, practice and the GATE syllabus.
52 questions, by topic and year
How many questions each topic had in the CS papers of each year. This shows what was asked, not what will be asked. We placed each question under a topic ourselves; the exam paper does not label topics.
| Topic | 2018 | 2020 | 2022 | 2023 | 2024 | 2025 | 2026 | Total |
|---|---|---|---|---|---|---|---|---|
| Layering & switching | 1 | · | · | · | · | 1 | · | 2 |
| Performance | · | · | 1 | 1 | 1 | 1 | 3 | 7 |
| Data link & MAC | 1 | · | · | · | 1 | · | 1 | 3 |
| Routing | · | · | 1 | 1 | · | 1 | · | 3 |
| IPv4 | 1 | 2 | 2 | 1 | 7 | 4 | 3 | 20 |
| TCP | 2 | 1 | 1 | 1 | 2 | 2 | 3 | 12 |
| DNS & HTTP | · | 1 | 1 | 1 | 1 | · | 1 | 5 |
Solved papers
GATE CSE question papers with solutions: 2026 Set 1, 2026 Set 2, 2025 Set 1, 2025 Set 2, 2024 Set 1, 2024 Set 2, 2023, 2022, 2020, 2018
GATE 2023 comes from IIT Kanpur's own copy of the paper and its answer key, which numbers the CS questions Q.11 to Q.65. For 2024, 2025 and 2026 both sessions (CS1 and CS2) are included.
37 practice questions
The GATE syllabus for Computer Networks, paper by paper
From the GATE 2027 syllabus PDF: CS Section 10, “Computer Networks”.
Show the GATE CS wordingHide the GATE CS wording
Principles of Layering; Basics of switching (circuit, packet and virtual circuit) and performance metrics; Data link layer: error detection, Medium Access Control, Ethernet; Distance vector and link state routing; IPv4 - Fragmentation, CIDR Notation, Network Address Translation; TCP- flow control and congestion control, socket API; DNS and HTTP.
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Other exams
10 questions on Computer Networks from ISRO's Scientist/Engineer written test (ISRO CS 2025, ISRO CS 2023), by topic. They are not counted in the GATE numbers on this page.
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