Ls Routing Algorithms — Test 1

Correct Answer: B. B. Distance vector routing
Explanation: Originally, the ARPANET used distance vector routing in it but later it was replaced by link state routing. This is because of the count-to-infinity problem in distance vector routing. Unlike DVR, routing tables in LS routing contain whole topology of the network.

Correct Answer: A. A. True
Explanation: In link state routing, the routing tables are different but the topology they perceive is same. Because of this same topology, each node will have a shortest path for every node in the network.

Correct Answer: D. D. Spreading link state packets
Explanation: Link state packets are used to spread the information about the topology from one node to all nodes. It can be periodic or triggered and it carries information about both topology and itself to other nodes.

Correct Answer: C. C. Age
Explanation: Every link state packet, which is created by a node will have the data about its age. This age information is used to dispose the old packets from the domain which are timed out.

Correct Answer: A. A. Creating lsp €? flooding €? shortest path tree €? calculating routing table
Explanation: Once all nodes get familiar with the topology using flooding, which is done using LSP, then a shortest path tree will be constructed for each node. Shortest path trees are used to calculate the routing tables and each router will have one shortest path tree.

Correct Answer: C. C. Dijkstra algorithm
Explanation: Shortest path trees will be constructed to build the routing tables and router uses Dijkstra algorithm to compute the routes. Dijkstra algorithm finds the shortest route for every destination in the network for a router and this information will be memorized.

Correct Answer: A. A. Ospf
Explanation: Open shortest path first(OSPF) is based on link state routing which works in an autonomous domain and it is a dynamic routing protocol. This protocol works well by dividing the autonomous system into areas.

Correct Answer: C. C. Less routing loops
Explanation: Link state routing causes less loops when compared to distance vector routing. It is because, complete topology information will be there at each router and this information prevents misunderstandings which leads to loops.

Correct Answer: C. C. Link state advertisement
Explanation: Routers share the information about topology using link state advertisements. There will be a continuous process of passing these link state advertisements until every router get the full topology of the network.

Correct Answer: B. B. False
Explanation: Link state routing can be used within the autonomous system only, because flooding is unmanageable in a large network. Because, network is a collection of such autonomous systems.