4.

Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 223.1.17/24. Also suppose that Subnet 1 is required to support at least 60 interfaces, Subnet 2 is to support at least 90 interfaces, and Subnet 3 is to support at least 12 interfaces. Provide three network addresses (of the form a.b.c.d/x) that satisfy these constraints.

5.

The network shown in (num5)the above figure is a snapshot of a practical network consisting of seven routers.

The load on each link is normalized to a number indicated on that link.

Find the least-cost path between the two routers R1 and R7, using Dijkstras algorithm.

Show an iteration graph as the least-cost path is developed in (a).

Find the least-cost path between R1 and R7, using the Bellman-Ford algorithm.

Show an iteration graph as the least-cost path is developed in (c).

6.

What are some of the possible services that a link-layer protocol can offer to the network layer? Which of these link-layer services have corresponding services in IP? In TCP?

12 8 R2 R4 R5 3 3 R7 8 3 7 R1 R3 R6 9