For the Ch3 HW 48 problem, please complete the following steps
1. Using the tree method. Show the tree at the end of each step.
2. Using the table method. Create a table that shows (for each node):
1. The total distance from node D
2. The next node (via)
The main difference between the methods
• the first method shows all possible known nodes as dashed-possibilities and picks the shortest one (making the selection a solid line)
• the second method always picks the next node by selecting the next destination node with the next shortest total distance from the source node to next destination node, but
ignores nodes that aren't the next shortest total distance
Like we discussed at the end of class, if two nodes have the same next shortest total distance from source node, just pick one. Both methods will generate the same optimal outcome
(shortest total distances from a source node to all other nodes) regardless of which of the equal total distance nodes that you pick next.
48. For the network given in Figure 3.53, show how Dijkstra's shortest-path algorithm builds the routing table for node D. Create a routing database (table) similar to Table 3.14 on
page 258. (You may find it more useful to number the steps as listed in the algorithm on page 257.) Illustrate the progression of the algorithm using Radia Perlman's technique as
illustrated on slides 7-8 through 7-14. Draw one tree for each pass through the algorithm. After each iteration, also create the resulting routing table (similar to the routing table
on slide 7-14). The tree for the first pass is shown below. The tables and trees may be drawn by hand and scanned or photographed for submission to Canvas. (10 points)
3
A
C
6
8
1
B
2
D
E
2
End of
Pass 1*
D Next
8
2
A
E
Neighbor Neighbor
Figure 3.53 Network for Exercises 46, 48 and 54.
