Q1: | Why must a computer be configured for IP forwarding to act as a router? |
A1:
| A router receives datagrams that have addresses other than its own. Typically, the TCP/IP software will ignore a datagram if it is addressed to a different host. IP forwarding provides a means for accepting and processing datagrams that must be forwarded to other networks. |
Q2: | Why is link state routing better for larger networks? |
A2:
| Distance vector routing is not efficient for large numbers of routers. Each router must maintain a complete table of destinations. Network data is altered at each step in the propagation path. Also, entire routing tables must be sent with each update even though most of the data might be unnecessary. |
Q3: | What is the purpose of the exterior router? |
A3:
| The exterior router is designated to exchange routing information about the autonomous system with other autonomous systems. Assigning this role to a specific router protects the other routers in the system from having to get involved with determining routes to other networks. |
Q4: | Why does RIP set a maximum hop count of 15? |
A4:
| If the number of routers becomes too large, problems can result from the slow convergence of the routers to an equilibrium state. |