Computer Networks · M2 · mocks

Q4 · OSPF operation and packets

M2 mock B

Q1(a)+Q1(b) compulsory; choose any two of Q2/Q3/Q4 · 10 marks attempted

Question. Explain how OSPF learns the topology and selects a route. Name its five packet types. [3 practice marks]

Answer

OSPF exchanges and maintains link-state information, builds a topology database and runs Dijkstra’s shortest-path computation rooted at the local router. It chooses a path with the lowest sum of link costs and installs the corresponding next hop. Equal-cost paths may be supported.

Five packet types: Hello, Database Description, Link State Request, Link State Update and Link State Acknowledgment.