Difference between Distance vector and Link State protocol?

 Distance Vector Protocol :

1. Entire routing table is sent as an update
2. Distance vector protocol send periodic update at every 30 or 90 second
3. Update are broadcasted
4. Updates are sent to directly connected neighbor only
5. Routers don’t have end to end visibility of entire network.
6. Distance vector routing protocol network may have patch in network carrying wrong information
7. 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 :

1. Updates are incremental & entire routing table is not sent as update
2. Updates are triggered not periodic
3. Updates are multicasted
4. Update are sent to entire network & to just directly connected neighbor
5. Updates are carry SPF tree information & SPF cost Calculation information of entire topology
6. Routers have visibility of entire network of that area only.
7. No routing loops
8. Convergance is fast because of triggered updates.

Eg. : OSPF , IS-IS