Consider the network in Figure 1. Suppose that host A just connected to the network and has an empty ARP table. Suppose that the ARP tables at other hosts are up to date.

a) How many subnets are there in this network? List the interfaces in each subnet (by their IP

address and MAC address).

b) Suppose A is a mobile host (e.g., laptop). How does A obtain its IP address? How does it obtain

its MAC address?

c) Suppose B is a server whose hostname is known to A. A wants to send a packet to B. How does A

know B IP address?

d) In the packet sent by A destined to B, what are the values of these header fields: MAC src, MAC

dest, IP src, IP dest?

e) How does A know the IP address of the left interface of R1 (i.e., IP3)? How does A know the MAC

address of this interface (i.e., MAC3)?

f) Repeat d) for the packet sent by R1 (i.e., the frame containing the A-to-B IP datagram that is

sent by R1).

R1 R2 IP 1 MAC1 IP7 ???7 IP4 MAC4 P6 MAC6 IP2 MAC2 IP3 MAC3 IP8 MAC8 ???5