Solutions to End of Chapter Problems
Problem 1:
(a)
Link state algorithms respond better since they are not prone to the count-to-infinity
problem. A new LSP with the correct information is flooded throughout the network.
(b)
The node in question is advertising that it is able to instantly reach every other node.
Neighboring nodes will route most (if not all) traffic via this node. This node will
become a "black hole".
(c)
If A tells B that it has a path to node C, there is no way for B to know if the path that A is
advertising has B as a part of it. See the pictorial example in the notes.
(d)
Answer is (ii)
Problem 2:
From B
(7)
A
4
B
0
C
8
D
13
E
7
F
2
Problem 3:
(a)
From D
(4)
A
17
B
11
C
6
D
0
E
8
F
10
B, D and E
(b)
C
B
D
E
(c)
From E
(6)
A
8
B
6
C
2
D
10
E
0
F
4
6
1
1
Routing Table for Router C:
Destination Next element Weight
A
E
7
B
E
5
D
D
1
E
E
1
F
E
4
G
E
5
(d) Routing Table for Router E:
Destination Next element Weight
A
F
6
B
F
4
C
C
1
D
C or D
2
F
F
3
G
F
4
6
Destination Next
Hop
A
B
B
B
D
D
E
E
F
B
Delay
11
7
4
6
9
Problem 4:
Routing Table for Router A:
Destination Next element Weight
B
G
2
C
G
8
D
G
9
E
G
5
F
G
4
G
G
1
H
H
2
Problem 5:
(a) Distance vector
(b) Link state
Problem 6:
Destination
A
B
C
D
E
Next element
A
I
I
E
Total cost
5
3
0
2
5
7