Which algorithm does IS-IS use to determine the shortest path through a network?

A.
Bellman-Ford routing algorithm

B.
Johnson’s algorithm

C.
Dijkstra’s algorithm

D.
Floyd-Warshall algorithm

Explanation:
Dijkstra’s algorithm is an algorithm for finding the shortest paths between nodes in a graph, which may represent, for example, road networks.
The shortest path algorithm is widely used in network routing protocols, most notably IS-IS and Open Shortest Path First (OSPF).
DUAL, the Diffusing Update ALgorithm, is the algorithm used by Cisco’s EIGRP routing protocol to ensure that a given route is recalculated globally whenever it
might cause a routing loop. It was developed by J.J. Garcia-Luna-Aceves at SRI International.