Computer Networks GATE CSE PYQ Topic Wise (2016–2026)

Explore: GATE CS hub · All GATE CS topics · Syllabus & pattern · GATE CS 2026

Answer first

Computer Networks has appeared in 11 of the 11 official GATE CS papers from 2016–2026, with 56 questions in all. It averages 8.2 marks a year, which puts it 4th of 11 technical subjects. The last three papers gave it 8 (2026), 6 (2025), 9 (2024).

The concepts that came back most often are TCP, Application Layer, Routing. TCP, Application Layer appeared in at least 7 of the 11 years. 38% of the questions are NAT, so you have to work out an exact value with no options to eliminate.

Marks per year

One official set per year (set 1 where GATE CS ran two sessions). Marks are as printed in the official answer key.

Most-asked concepts

Sorted by how many years a concept appeared in, then by marks.

How to practise Computer Networks from these PYQs

1. Start with the concepts at the top of the table above. They repeat, so they pay off first.
2. Open the official PDF for a year, solve only that year’s CN questions against the clock (about 3 minutes a mark), then check the official key listed below.
3. Log each miss by concept and type (MCQ, MSQ, NAT). An MSQ with one extra option scores zero, so log those separately.
4. Once a concept is clean across two or three years, move on to the next one.
5. Then sit a full year paper from the GATE CS hub so the subject drill turns into exam timing.

Questions by year

Each line gives the official question number, marks, type and concept, our one-line summary and the official key. The full question is in the official PDF linked under each year.

GATE CS 2026 (CS1)

• Q.18 · 1 mark · MCQ · TCP: True statement about TCP connection setup and teardown (key: D)
• Q.19 · 1 mark · MSQ · Application Layer: HTTP 1.1 persistent connections and pipelining (key: A, C, D)
• Q.44 · 2 marks · MCQ · TCP: Time for TCP slow start to reach a congestion window size (key: B)
• Q.45 · 2 marks · MCQ · Sliding Window: Window size needed for full utilisation of a link (key: B)
• Q.56 · 2 marks · MSQ · IP Addressing & Subnetting: CIDR blocks an ISP can assign for 6000 addresses (key: A, B, C)

Paper: official PDF · GATE CS 2026 page

GATE CS 2025 (CS1)

• Q.16 · 1 mark · MCQ · Layers & Headers: Match OSI layers to their functions (key: B)
• Q.22 · 1 mark · MSQ · TCP: TCP header flags set in the three-way handshake packets (key: B, D)
• Q.40 · 2 marks · MCQ · Routing: Interface chosen for a destination IP by longest prefix match (key: A)
• Q.57 · 2 marks · NAT · IP Fragmentation: Number of fragments for a 15000-byte message through two routers (key: 7)

Paper: official PDF · GATE CS 2025 page

GATE CS 2024 (CS1)

• Q.16 · 1 mark · MCQ · Application Layer: Number of HTTP/TCP exchanges to fetch a page with embedded images (key: C)
• Q.29 · 1 mark · MSQ · TCP: Sequence and acknowledgement numbers in a TCP three-way handshake (key: A, D)
• Q.31 · 1 mark · MSQ · IP Addressing & Subnetting: IP header fields modified by a NAT device on outbound packets (key: A, C)
• Q.36 · 2 marks · MCQ · Delay & Throughput: Time to send a file in chunks over a multi-hop store-and-forward path (key: B)
• Q.58 · 2 marks · NAT · Routing: Count addresses forwarded to a next hop by longest prefix match (key: 40)
• Q.65 · 2 marks · NAT · IP Fragmentation: Number of fragments when a datagram crosses links with smaller MTUs (key: 6)

Paper: official PDF · GATE CS 2024 page

GATE CS 2023

• Q.17 · 1 mark · MCQ · Sliding Window: Scenario with lowest link utilisation under stop-and-wait (key: B)
• Q.25 · 1 mark · MSQ · Routing: Incorrect statements about the OSPF routing protocol (key: A, C)
• Q.50 · 2 marks · MSQ · TCP: Valid design choices for sequence number and window fields of a TCP-like protocol (key: B, C, D)
• Q.52 · 2 marks · MSQ · Application Layer: Statements about DNS lookups and HTTP requests when opening a URL (key: C, D)
• Q.65 · 2 marks · NAT · Routing: Interface chosen by longest prefix match for a destination address (key: 3)

Paper: official PDF · GATE CS 2023 page

GATE CS 2022

• Q.22 · 1 mark · MCQ · IP Addressing & Subnetting: Number of subnets in an enterprise network with routers and a firewall (key: C)
• Q.35 · 1 mark · NAT · Application Layer: Number of DNS query-response pairs for iterative resolution of a domain (key: 4)
• Q.55 · 2 marks · MSQ · Routing: Which CIDR prefixes can be forwarded via each next hop of a routing table (key: B,D)
• Q.57 · 2 marks · NAT · Routing: Count-to-infinity behaviour of distance vector routing after a link failure (key: 0.5)
• Q.59 · 2 marks · NAT · Delay & Throughput: Time to receive a packet over a satellite link with propagation delay (key: 7.07–7.09)
• Q.60 · 2 marks · NAT · TCP: Minimum TCP sequence number bits to avoid wraparound within the MSL (key: 33)

Paper: official PDF · GATE CS 2022 page

GATE CS 2021 (set 1)

• Q.8 · 1 mark · MCQ · Data Link Layer: Destination MAC addresses of ARP requests and replies (key: C)
• Q.29 · 2 marks · MCQ · Error Detection: Find check bits of a 12-bit Hamming codeword (key: A)
• Q.44 · 2 marks · MSQ · TCP: Client behaviour after a TCP server crashes and reboots (key: A, B, C)
• Q.45 · 2 marks · MSQ · Routing: IP fragmentation of a TCP segment across two MTUs (key: A, C)
• Q.49 · 2 marks · NAT · Sliding Window: Sequence-number bits for a sliding window protocol (key: 50–52)

Paper: official PDF · GATE CS 2021 page

GATE CS 2020

• Q.15 · 1 mark · MCQ · Routing: Statements about what an IP router does (key: D)
• Q.25 · 1 mark · NAT · Application Layer: TCP connections needed to fetch a page in non-persistent HTTP (key: 6)
• Q.38 · 2 marks · MCQ · IP Addressing & Subnetting: CIDR block assigned to an organisation with 1500 hosts (key: B)
• Q.55 · 2 marks · NAT · TCP: Time for a TCP sender to reach full window under slow start (key: 44)

Paper: official PDF · GATE CS 2020 page

GATE CS 2019

• Q.16 · 1 mark · MCQ · Application Layer: Protocol pair used to send and then retrieve e-mail (key: B)
• Q.28 · 2 marks · MCQ · IP Addressing & Subnetting: Which hosts share a subnet under a /30 mask (key: C)
• Q.29 · 2 marks · MCQ · Data Link Layer: How a host finds the MAC address of another host via ARP (key: C)
• Q.49 · 2 marks · NAT · Data Link Layer: Minimum 8-port switches to connect 15 machines (key: 3)
• Q.54 · 2 marks · NAT · Network Security: Find a prime factor of an RSA modulus from its totient (key: 97)

Paper: official PDF · GATE CS 2019 page

GATE CS 2018

• Q.13 · 1 mark · MCQ · Layers & Headers: Match header fields to their bit lengths (key: C)
• Q.14 · 1 mark · MCQ · TCP: Statements about TCP slow start (key: C)
• Q.25 · 1 mark · NAT · TCP: Time before TCP sequence numbers wrap around (key: 34–35)
• Q.54 · 2 marks · NAT · IP Fragmentation: IP offset of the last fragment of a forwarded packet (key: 144)
• Q.55 · 2 marks · NAT · MAC Protocols: Timing bound that avoids collisions in a carrier-sense MAC scheme (key: 50)

Paper: official PDF · GATE CS 2018 page

GATE CS 2017 (set 1)

• Q.14 · 1 mark · MCQ · TCP: TCP connection state after client close and server ACK (key: D)
• Q.15 · 1 mark · MCQ · Network Security: Possible security violations against a digitally signed message (key: B)
• Q.32 · 2 marks · MCQ · Error Detection: CRC-encoded message for a given generator polynomial (key: C)
• Q.44 · 2 marks · NAT · Network Security: RSA private key from given primes and public key (key: 11.0)
• Q.45 · 2 marks · NAT · Sliding Window: Link utilisation of stop-and-wait ARQ with given parameters (key: 86.5–89.5)

Paper: official PDF · GATE CS 2017 page

GATE CS 2016 (set 1)

• Q.24 · 1 mark · MCQ · Application Layer: Which protocol does not map one address form to another (key: C)
• Q.25 · 1 mark · MCQ · Application Layer: Identify stateful application layer protocols (key: C)
• Q.52 · 2 marks · MCQ · Network Security: Keys used to sign and verify a digitally signed message (key: B)
• Q.53 · 2 marks · NAT · IP Fragmentation: Number of fragments for a datagram over a 100-byte MTU link (key: 13.0 : 13.0)
• Q.54 · 2 marks · NAT · TCP: Maximum burst duration with a token bucket (key: 1.1 : 1.1)
• Q.55 · 2 marks · NAT · Sliding Window: Minimum frame size for stop-and-wait ARQ efficiency (key: 2500.0 : 2500.0)

Paper: official PDF · GATE CS 2016 page

Other GATE CS subjects

• General Aptitude
• Engineering Mathematics
• Discrete Mathematics
• Digital Logic
• Computer Organization & Architecture
• Programming & Data Structures
• Algorithms
• Theory of Computation
• Compiler Design
• Operating Systems
• Databases (DBMS)

FAQ

How many marks does Computer Networks carry in GATE CS?

Across the official GATE CS papers from 2016–2026 (one set per year), Computer Networks carried 8.2 marks a year on average, from 6 in 2025 to 10 in 2022.

Which Computer Networks topics repeat most in GATE CS?

By the number of years they appeared in: TCP, Application Layer, Routing. The concept table on this page lists every concept with its question count and years.

Are these the official GATE CS Computer Networks questions?

Yes. Each question comes from the official GATE CS question paper for that year, and the key, marks and question type come from the official answer key. Summaries are ours; open the official PDF for the full question.

What question types does Computer Networks use in GATE CS?

Of 56 questions: 24 MCQ, 11 MSQ and 21 NAT. MSQ only appears from 2021 onwards. 34 of the 56 questions carry 2 marks.