OSPF Router Types

OSPF Router Types

Designated Router

Backup Designated Router

Internal Router

Backbone Router

Area Border Router

Autonomous System Boundary Router


Designated Router

Every OSPF area will select one DR and BDR. DR will be the primary router for the area and all other router will send LSA (Link State Advertisement) to DR. DR will keep track of all link state updates and make sure LSA's are flooded to rest of the network using Multicast IP (224.0.0.6).

Backup Designated Router

BDR is the Secondary router in the OSPF area. It will be selected during the election process. If DR fails it will take the role of DR. 

Note: There won't be any re-election until new DR fails. If old DR router come up also it cannot become DR. 

Router doesn't wants to participate in DR & BDR election set router priority "0".

Internal Router

Routers with in the same area will be called as internal routers.

Backbone Router

Router's one or more interface connected to Area 0 is called as Backbone router.

Area Border Router

In OSPF Router connecting to more than one area will be called as ABR.

Autonomous System Boundary Router

Router which are connecting from other Autonomous System (RIP & EIGRP).