OSPF Network Types IP With Ease

There are five different network types within which OSPF operates. The following list explains the characteristics of the OSPF network types:

* The Broadcast network type is the default for an OSPF enabled Ethernet interface.
* The Broadcast network type requires that a link support Layer 2 Broadcast capabilities.
* The Broadcast network type has a 10 second hello and 40 second dead timer.
* An OSPF Broadcast network type requires the use of a DR/BDR.

* The Non-Broadcast network type is the default for OSPF enabled frame relay physical interfaces.
* Non-Broadcast networks requires the configuration of static neighbors; hello’s are sent via unicast.
* The Non-Broadcast network type has a 30 second hello and 120 second dead timer.
* An OSPF Non-Broadcast network type requires the use of a DR/BDR

* A Point-to-Point OSPF network type does not maintain a DR/BDR relationship.
* The Point-to-Point network type has a 10 second hello and 40 second dead timer.
* Point-to-Point network types are intended to be used between 2 directly connected routers.

Point-to-Multipoint Non-Broadcast
* Same as Point-to-Multipoint but requires static neighbors. Used on Non-broadcast layer 2 topologies.
* Gives you the ability to define link cost on a per neighbor basis.

* OSPF treats Point-to-Multipoint networks as a collective of point-to-point links.
* Point-to-Multipoint networks do not maintain a DR/BDR relationship.
* Point-to-Multipoint networks advertise a hot route for all the frame-relay endpoints.
* The Point-to-Multipoint network type has a 30 second hello and 120 second dead timer.

Comparison Table: OSPF Network Types
To summarize , we can enumerate the OSPF Network Types in the below table –

Non-BroadcastFully MeshedSameManual configurationDR/BDR elected

RFCBroadcastFully MeshedSameAutomaticDR/BDR elected

CiscoPoint-to-multipointPartial Mesh or StarSameAutomaticNo DR/BDR

RFCPoint-to-multipointNon broadcast

Partial Mesh or StarSameManual configurationNo DR/BDR

CiscoPoint-to-pointPartial Mesh or star, using sub interfaceDifferent for each subnetAutomaticNo DR/BDR

CiscoDownload the table: OSPF Network Types

Continue Reading:
OSPF LSA Types The Ultimate Guide

OSPF Router Types: Detailed Explanation

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About The Author
Rashmi Bhardwaj
I am here to share my knowledge and experience in the field of networking with the goal being – “The more you share, the more you learn.” I am a biotechnologist by qualification and a Network Enthusiast by interest. I developed interest in networking being in the company of a passionate Network Professional, my husband. I am a strong believer of the fact that “learning is a constant process of discovering yourself.” – Rashmi Bhardwaj (Author/Editor)