Consider LAN above, (a) Assign an IP address to the leftmost interface of the router, given that the subnet mask is 255.255.255.0. (3 marks) (b) Suppose A wants to send an IP datagram to B and knows B's IP address. Must A also know B's MAC address to send the datagram to B? (3 marks) (c) Suppose A wants to send an IP datagram to C and knows C's IP address. Must A also know C's MAC address to send the datagram to C? If so, how does A get this info? If not, explain why not. (3 marks) (d) Suppose that R has a datagram (that was originally sent by A) to send to C. What are the MAC addresses on the frame that is sent from R to c ? What are the IP addresses in the IP datagram encapsulated within the frame? (5 marks) (e) Suppose the switches above are learning switches and suppose that the switch has just been turned on. Suppose now A send an Ethernet frame to B. On how many outgoing switch interfaces will this first frame be carried? Now suppose that B replies to A and A sends a second frame to B, on how many outgoing switch interfaces will thus second frame be carried? (5 marks) (f) Suppose now that the router is removed from the network depicted above. Explain if all nodes can keep their IP addresses and still be able to communicate with all other nodes