1- In the following network, assume the distance value for the links
connecting any pair of routers is equal to 1. Also assume router C sends a
broadcast message using:
a. Spanning Tree
b. Reverse Path Forwarding
Computer the total number of the messages sent using each method. Draw
the diagrams supporting your answer.
2- Assume a block of IP addresses as 140.120.x.y is allocated to a company having
9 departments. The company wants to define one subnet for each department.
a. Define the subnet masks
b. Compute the number of hosts in each subnet
c. Find the range of IP addresses in the second subnet
d. Describe how the router connecting these subnets forwards the packets. (use
an example)
3- Consider the network below, but ignore the weights on the lines.
Suppose that it uses flooding as the routing algorithm. If a packet sent by A
to D has a maximum hop count of 3, list all the routes it will take. Also tell
how many hops worth of bandwidth it consumes.
Solution 3:
The packets are sent in the following directions:
A
G
B
E
C
D
F
G
E
F
B
H
F
D
F
The total number of messages sent is 14
In a network link state routing is used for updating routing information.
Router F measures its distance to its neighbors as follows:
To:
A=3
B=4
C=2
It receives the following packets:
From A: (E=4, B=6, F=3)
From B: (A=6,C=5,D=3,E=5,F=4)
From C: (B=5,D=7,F=2)
From D: (B=3,C=7)
From E: (A=4,B=5)
Draw the network diagram and find the shortest path from F to D
E
5
4
6
A
3
B
F
2
3
D
4
7
C
The shortest path using Dijkstra algorithm from F to D is F-B-D with a length of 7 (Try to show all steps of
the algorithm)