014.01.62.1. Can you explain the role of the Address Resolution Protocol (ARP) in the context of IP over Ethernet and why it is necessary for the host to know the MAC address corresponding to the destination IP address when constructing an Ethernet frame for an IP packet?
This question assesses the candidate's understanding of ARP and its importance in the process of mapping IP addresses to MAC addresses in an Ethernet network. It also gauges their comprehension of the necessity for MAC addresses in the Ethernet frame construction.
The host places an IP packet inside an ethernet frame to transmit the packet across the physical layer to another host. Frames do not include IP address information, they use MAC(network) address. This is called as Address Resolution Protocol(ARP). A host using ethernet as its physical layer and IP as the network layer maintains a small table called an ARP cache that maps IP addresses to MAC addresses.
