In link state routing algorithm after construction of link state packets, new…

Answer: Dijkstra’s algorithm is used to compute new routes in link-state routing.

Reason: After routers flood and collect link-state packets, each router has a complete map of the network topology represented as a weighted graph. Dijkstra’s algorithm finds the shortest paths from that router to every other router using that graph.

• Build the network graph from received link-state packets (nodes = routers, edges = links with costs).

• Run Dijkstra’s algorithm on the graph to compute the shortest path from the local router to every other router.

• Populate the routing table with next hops and costs derived from the shortest-path tree.

Why the other choices are incorrect:

• DES algorithm is an encryption algorithm and is not used to compute routing paths.

• RSA algorithm is a public-key cryptosystem, unrelated to route computation.

• "Packets" refers to units of data, not an algorithm for calculating new routes.

Complexity: Dijkstra’s algorithm runs in about O(V^2) for a simple implementation or O(E + V log V) when implemented with a priority queue, where V is the number of routers and E the number of links.