GATE CS 2025 Set 2 | Question 16

MCQ · 1 mark · −0.33

Consider the following statements:

(i) Address Resolution Protocol (ARP) provides a mapping from an IP address to the corresponding hardware (link-layer) address.

(ii) A single TCP segment from a sender S to a receiver R cannot carry both data from S to R and acknowledgement for a segment from R to S.

Which ONE of the following is CORRECT?

  1. Option A: Both (i) and (ii) are TRUE
  2. Option B: (i) is TRUE and (ii) is FALSE (correct)
  3. Option C: (i) is FALSE and (ii) is TRUE
  4. Option D: Both (i) and (ii) are FALSE

Answer

(B)

Explanation

(i) is TRUE. A host that knows the IP address of a machine on its local network still needs that machine’s link-layer (MAC) address to build a frame. ARP broadcasts a request for that IP address and gets back the matching hardware address.

(ii) is FALSE. TCP is full duplex, and every segment header has an acknowledgement number field, so a segment carrying data from S to R can also acknowledge data received from R. This is called piggybacking, and it is the normal case when both sides are sending.

Answer: B