Suppose that ComputerA is trying to connect with another computer on the same network (ComputerB) with an IP address of 192.168.1.200. Describe what happens in making the connection.

Question

What will be an ideal response?

Answer 1

1. By examining the IP address and subnet mask, ComputerA determines that the two computers are on the same network. ComputerA then checks its ARP cache (storage area) to see if it already has the MAC address for the IP address of ComputerB.
2. If ComputerA does not have the address, then ARP sends out a packet to look for the address. The packet is a request for the MAC address for host 192.168.1.200.
3. All of the computers on the network examine the packet, but only the computer with the right IP address (ComputerB) responds. When ComputerB sees this request, it puts the MAC address for ComputerA into its own ARP cache and then sends back its MAC address to ComputerA.
4. ComputerA puts the MAC address into its ARP cache, and communication continues. The MAC address remains in the cache for 2 to 10 minutes, depending on how often the address is used. If the two computers are not on the same network and the information needs to cross a router, a similar process occurs, except that the ARP request asks for the MAC address of the router.