Again referring to Figure 21.12, assume that A is a mobile node and that LAN X is a foreign network for A. Assume that an IP datagram arrives at R1 from the Internet to be delivered to A. Show the format of the IP datagram arriving at R1 and the MAC frame leaving R1 (include the IP header or headers) for the following cases:

a. IP-to-IP encapsulation is used and R1 is the care-of address.

b. Minimal encapsulation is used and R1 is the care-of address.

c. IP-to-IP encapsulation is used and A is the care-of address.

d. Minimal encapsulation is used and A is the care-of address.