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 :
- Max Hop Count
- Spliti horizon
- Route poisoning
- Hold down Timer
Distance vector routing protocol has slow convergance due to periodic update. Eg. RIP ,IGRP , BGP .
Link state protocol :
- Updates are incremental & entire 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