Question

Consider the following two statements.
\[ S_1 : \text{Destination MAC address of an ARP reply is a broadcast address.} \] \[ S_2 : \text{Destination MAC address of an ARP request is a broadcast address.} \] Which one of the following choices is correct?

• A. Both \(S_1\) and \(S_2\) are true.
• B. \(S_1\) is true and \(S_2\) is false.
• C. \(S_1\) is false and \(S_2\) is true.
• D. Both \(S_1\) and \(S_2\) are false.

Hint:

ARP requests are broadcast because the destination MAC is unknown, while ARP replies are unicast.

Answer 1

The Correct Option is C

Step 1: Analyze ARP request behavior.
An ARP request is generated when a host knows the IP address of a destination but does not know its MAC address.

Since the destination MAC address is unknown, the ARP request must be sent to all hosts in the local network.

Hence, an ARP request is sent as a broadcast frame, making statement S₂ true.

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Step 2: Analyze ARP reply behavior.
An ARP reply is sent by the host whose IP address matches the request.

At this point, the responder knows the MAC address of the requester (from the ARP request), so the reply is sent directly to that host.

Therefore, an ARP reply is a unicast frame, not a broadcast, making statement S₁ false.

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Final Conclusion:
S₁ is false and S₂ is true.

Final Answer: (C)