Question

1. (2pt) Compare and contrast link-state and distance-vector routing algorithms.

Answer 1

Compare and contrast link state and distance vector routing algorithm:

Distance Vector Routing Algorithm Link State Routing Algorithm Distance Vector is dynamic routing Link State is dynamic routing algorithm in algorithm in which each router computes the which each router shares the routing distance and exchange t routing information of its neighbors with all the other information or data to its directly connected routers in the given network. neighbors Consider the given ISDN network where Consider the given ISDN network where each router uses distance vector algorithm. each router uses Link state algorithm. Link Distance vector protocol chooses the path state protocol chooses the path ACBD as it From A to B even if it's slowest link of the uses faster link network. 128k 128k 100b Tx 100bTx 100bTx 100b Tx 100bTx 100b Tx

Distance vector routing method requires two Where in contrast, Link state routing method parameters: the distance of a route requires all the routers to know all the destination and the direction vector to the various paths to reach every other router in destination. the network. For the derivation of routing table, it uses For the derivation of routing table, it uses Bellman Ford Algorithm Dijkstra's Algorithm. Calculate the best path based on least no. of Calculate the best path based on the cost host Routing table updates are periodic at every Routing table updates are triggered 30 or 90 second Example: IGRP, BGP, RIP Distance Vector routing method has slow Link State routing method has faster Example: OSPF, IS-IS convergence convergence Routing table updates are Broadcasted Routing table updates are Multicasted

It requires more memory It requires less memory. Bandwidth available is more Bandwidth required is less It includes Update of entire routing table. It updates only link state not entire table. It also can have persistent routing loops There is only transient loop It has Less Traffic. All the routers don't have It has More traffic. All the routers have visibility of the other al router in the visibility of the other all routers in the network. particular area of the network.