a$.$ Show the appropriate IP and MAC addresses in the given network topology.

b$.$ Consider sending an IP datagram from Host E to Host B$.$ Suppose all of the ARP tables are up to date. Enumerate all the steps.

c$.$ Repeat $($c$),$ now assuming that the ARP table in the sending host is empty $($and the other tables are up to date$).$

d$.$ Replace the router between subnets $1$ and $2$ with a switch S$1,$ and label the router between subnets $2$ and $3$ as R$1.$ Suppose E would like to send an IP datagram to B$,$ and assume that E$$s ARP cache does not contain B$$s MAC address. Will E perform an ARP query to find B$$s MAC address? Why? In the Ethernet frame $($containing the IP datagram destined to B$)$ that is delivered to router R$1,$ what are the source and destination IP and MAC addresses?

e$.$ Suppose now that the leftmost router in Figure $1$ is replaced by a switch. Hosts A$,$ B$,$ C$,$ and D and the right router are all star$-$connected into this switch. Give the source and destination MAC addresses in the frame encapsulating this IP datagram as the frame is transmitted $($i$)$ from A to the switch, $($ii$)$ from the switch to the right router, $($iii$)$ from the right router to F$.$ Also give the source and destination IP addresses in the IP datagram encapsulated within the frame at each of these points in time.