Q7. (25 pts) This question is related with ARP spoofing. a) What is the main purpose of ARP? b) Consider the below network structure in a LAN. Initially the source PC sends an ARP request to the network to get the target PC's MAC. Then the target PC sends an ARP reply. Respectively, both the source PC and the target PC insert an entry to their ARP cache tables. (i) What information will be in the inserted entries for both the source PC and the target PC? Fill in the corresponding boxes below. Attacker PC IP: 10:00:00:11 MAC: AA:AA:AA:AA:AA:AA Source PC ARP cache for the source IP: 10:00:00:21 MAC: BB:BB:BB:BB:BB:BB Target IP: 10:00:00:31 PC MAC: CCCCCCCCCC.CC ARP cache for the target (ii) Fill in the required fields (IP and MAC) of the Ethernet frames that include ARP request and ARP reply. Ethernet frame with ARP request Ethernet frame with ARP reply ----dest MAC--- ----src MAC---- ----Src MAC----- ARP ----src IP. ARP ---target MAC- ----target IP