Q85a

Consider a simple graph with unit edge costs. Each node in the graph represents a router. Each node maintains a routing table indicating the next hop router to be used to relay a packet to its destination and the cost of the path to the destination through that router. Initially, the routing table is empty. The routing table is synchronously updated as follows. In each updated interval, three tasks are performed.

For the graph given above, possible routing tables for various nodes after they have stabilized, are shown in the following options. Identify the correct table. $\overset{\text{Table for node A}}{\begin{array}{|c|c|c|} \hline \text {A} & \text{-} &\text{-} \\\hline \text{B}& \text{B} & \text{1} \\\hline \text{C}& \text{C} & \text{1} \\\hline \text{D}& \text{B} & \text{3} \\\hline \text{E}& \text{C} & \text{3} \\\hline \text{F}& \text{C} & \text{4} \\\hline \end{array}}$ $\overset{\text{Table for node C}}{\begin{array}{|c|c|c|} \hline \text {A} & \text{A} &\text{1} \\\hline \text{B}& \text{B} & \text{1} \\\hline \text{C}& \text{-} & \text{-} \\\hline \text{D}& \text{D} & \text{1} \\\hline \text{E}& \text{E} & \text{1} \\\hline \text{F}& \text{E} & \text{3} \\\hline \end{array}}$ $\overset{\text{Table for node B}}{\begin{array}{|c|c|c|} \hline \text {A} & \text{A} &\text{1} \\\hline \text{B}& \text{-} & \text{-} \\\hline \text{C}& \text{C} & \text{1} \\\hline \text{D}& \text{D} & \text{1} \\\hline \text{E}& \text{C} & \text{2} \\\hline \text{F}& \text{D} & \text{2} \\\hline \end{array}}$ $\overset{\text{Table for node D}}{\begin{array}{|c|c|c|} \hline \text {A} & \text{B} &\text{3} \\\hline \text{B}& \text{B} & \text{1} \\\hline \text{C}& \text{C} & \text{1} \\\hline \text{D}& \text{-} & \text{-} \\\hline \text{E}& \text{E} & \text{1} \\\hline \text{F}& \text{F} & \text{1} \\\hline \end{array}}$