(a)    What are Private IP addresses? Why are they needed? Describe how devices with private IP addresses can be connected to the Internet.
 

(b)    An Exterior Routing Protocol (ERP) is used to maintain routing information between autonomous systems. Explain why neither the distance vector algorithm nor the link state algorithm are suitable for use in ERPs.

(c)    Consider the following network configuration involving two LANs in the TCP/IP model:
•    Hosts H1 and H2 connected to LAN-0
•    Hosts H3 and S4 connected to LAN-1
•    A router R connected to both LAN-0 and LAN-1 via two interfaces a0 and a1 respectively. 

Describe the actions required at the Internet and Network Access layers of H3 when H3 sends an IP datagram to host H1.

(d)    Network protocols can provide reliable or unreliable service. What’s the difference between them? Why would one ever design a protocol to provide unreliable service? Give an example of an application where a reliable protocol would be a poor choice.