GATE CSE 2022 · Q35
Time
www.gate.org.in by a DNS resolver. Assume that no resource records are cached anywhere across the DNS servers and that iterative query mechanism is used in the resolution. The number of DNS query-response pairs involved in completely resolving the domain name is ________.Your answerNumerical answer
Solution
Official answer: 4 (±0)
DNS and HTTPIn an iterative DNS resolution where no records are cached, the local DNS resolver queries each authoritative level in the DNS hierarchy sequentially [cite: 1, 2]:
Query-Response Pair 1: The resolver queries a Root DNS server (.) and receives a referral to the .in Top-Level Domain (TLD) DNS server [cite: 2].
Query-Response Pair 2: The resolver queries the .in TLD server and receives a referral to the authoritative DNS server for org.in [cite: 2].
Query-Response Pair 3: The resolver queries the org.in DNS server and receives a referral to the authoritative DNS server for gate.org.in [cite: 2].
Query-Response Pair 4: The resolver queries the gate.org.in authoritative DNS server and receives the final IP address mapping for www.gate.org.in [cite: 2].
Hence, exactly 4 query-response pairs are involved in resolving the domain name [cite: 2].
Try the question first, then check your work.
Examiner trap
Count the hierarchy levels traversed iteratively by the resolver: Root (.) TLD (.in) Second-level domain (org.in) Authoritative server (gate.org.in).
This DNS and HTTP previous year question is Q35 of the GATE CSE 2022 paper. Find more GATE CSE PYQs on DNS and HTTP in Computer Networks, or browse all GATE CSE PYQs.
Free diagnostic
Take the 20-minute diagnostic: the 3 topics that cost you the most marks, and a rank range. Or sit 5 related DNS and HTTP PYQs now with no account.
An official question by email at 7 AM IST, with a link to its verified solution. Unsubscribe in one click.
DNS and HTTP has 18 GATE CSE PYQs across 15 papers from 2011 to 2026. 2 of them are 1-mark NAT questions like this one, and it is the only one in GATE CSE 2022.
How GATE tests DNS and HTTPIndependent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.