Interactive end-of-chapter exercises


Supplement to Computer Networking: A Top Down Approach 8th Edition


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Dijkstra's Link State Algorithm - Advanced

Consider the incomplete 6-node network shown below, with the given link costs.

Consider the completed table below, which calculates the shortest distance to all nodes from Z:
================================================
|    Node     |    Shortest distance from Z    |    Previous Node   |
================================================
       Z                                0                                     n/a   
       Y                                3                                     Z   
       W                               4                                     Y   
       V                                9                                     W   
       X                                9                                     Y   
       U                                10                                   W   
================================================



Question List


1. For link X, what is the cost associated with this link? If the answer can't be determined given the information, respond with 'n/a'

2. For link Y, what is the cost associated with this link? If the answer can't be determined given the information, respond with 'n/a'




Solution


1. The prior node in the path to X is Y, and we know the shortest distance of both X (9) and Y (3), so 9 - 3 = 6 which is X.

2. The prior node in the path to V is W, and we know the shortest distance of both V (9) and W (4), so 9 - 4 = 5 which is Y.



That's incorrect

That's correct

The answer was: 6

Question 1 of 2

The answer was: 5

Question 2 of 2

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