Chapter 6, Problem P15P

a.

Program Plan Intro

Figure 6.33:

The “Figure 6.33” contains:

• Two routers.
• Three switches (LAN).
• Three subnets.
  • Each subnet contains two host computers.
  • Subnet 1 contains two hosts named “A” and “B”. Both the two hosts are connected through a same switch.
  • Subnet 2 contains two hosts named “C” and “D”. Both the two hosts are connected through a same switch.
  • Subnet 3 contains two hosts named “E” and “F”. Both the two hosts are connected through a same switch.

Given consideration:

Consider that the switch is placed between Subnet 1 and Subnet 2, and the Router between them is named as R1.

b.

Explanation of Solution

Given: Consider the Host E needs to send a datagram to the Host B. Also, The Host E’s ARP cache does not holds B’s MAC address.

To find:

• Will the Host E execute ARP query to find the Host B’s MAC address.
• Source and destination IP and MAC addresses of the Ethernet frame that contains the IP datagram destined to B.

Solution:

“No”, the Host E do not executed ARP query to find out the MAC address of the Host B because, they are not on the common LAN...

c.

Explanation of Solution

Solution:

Actions of the switch S1:

The Switch 1 (S1) will program the Ethernet frame through its interfaces. The received ARP frame’s destination address is the broadcast address. It finds out that the Host A lives on Subnet 1 which is connected to the switch S1. The Switch S1 will then update its forwarding table to get an entry for Host A.

Router receives ARP request message:

“Yes”, the router R1 gets an ARP request message but this router will no forward the information to Subnet 3...