Host A wants to send a packet to Host C, but it doesn’t know Host C’s MAC addres
ID: 3596964 • Letter: H
Question
Host A wants to send a packet to Host C, but it doesn’t know Host C’s MAC address. What is the first packet sent by Host A using ARP to determine the destination’s MAC address? Please explain.
A. ARP request (who-has 131.204.128.2) unicast to Host C
B.ARP request (who-has 131.204.128.2) unicast to Host B
C.ARP request (who-has 131.204.128.2) broadcast to LAN
D. ARP reply(131.204.128.2 is 00:10:41:16:fe:24) broadcast to LAN
Host A 131.204.128.8 Host D Host B 131.204.128.18 Host C 131.204.128.2131.204.128.12 00:50:12:fb:76:c9 00:10:82:3d:7f.a2 00:10:41:16:fe:24 00:10:6f:72:b8:5eExplanation / Answer
Correct Option : C.ARP request (who-has 131.204.128.2) broadcast to LAN
Explanation:
ARP stands for Address Resolution Protocol. It is used for mapping a Internet Protocol address (IP address) to a physical address (MAC address).
Here Host A and Host C are in the same LAN. So to get the destination's MAC address, whish is Host C here, Host A first broadcasts an ARP request asking who has 131.204.128.2 (IP address of Host C) . This broadcasted packet would also contain Host A(sender) address. Since the packet is broadcasted, all the other hosts in the same LAN would recieve it. Now as the broadcasted packet has Host C 's IP address, Host C on recieving the packet would make a unicast ARP reply(131.204.128.2 is 00:10:41:16:fe:24) to Host A telling Host A its MAC address. Host B and Host D would just discard the broadcast packet recieved.
Thus Host A would know the MAC address of the destination which is Host C here.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.