Difference between Distance vector & Link State protocol


Distance Vector Protocol :


Entire routing table is sent as an update

Distance vector protocol send periodic update at every 30 or 90 second

Update are broadcasted

Updates are sent to directly connected neighbor only

Routers don't have end to end visibility of entire network.

Distance vector routing protocol network may have patch in network carrying wrong information

It is proned to routing loops

Routing loop avoidance Mechanism used are as below :

1> Max Hop Count
2> Spliti horizon
3> Route poisoning
4> Hold down Timer


Distance vector routing protocol has slow convergance due to periodic update.


Eg. RIP ,IGRP , BGP .






Link state protocol :


Updates are incremental & enitire routing table is not sent as update

Updates are triggered not periodic

Updates are multicasted

Update are sent to entire network & to just directly connected neighbor

Updates are carry SPF tree information & SPF cost Calculation information of entire topology

Routers have visibility of entire network of that area only.

No routing loops

Convergance is fast because of triggered updates.

Eg. : OSPF , IS-IS