OSPF Network Types Explained

OSPF Network Types are very important in OSPF. OSPF Protocol uses different OSPF Network Types. Some of these Network types are Standard and Some of them is Cisco Proprietary. So, what are these Open Shortest Path First Network Types?

 

Mainly,these OSPF Networks Types are given below:

• Broadcast Networks (Cisco Proprietary)
• Nonbroadcast Multi Access(NBMA) Networks
• Point-to-Point Networks (Cisco Proprietary)
• Point-to-Multipoint Networks
• Point-to-Multipoint Non Broadcast Networks (Cisco Proprietary)

 

As you can see, some of these network types are standard based and some of them are Cisco proprietary. Standard ones can be used in all vendors. But the Cisco proprietary types are used only with Cisco products. Now, let’s explain, each of these network types with entwork diagrams.

 

OSPF Network Types: Broadcast Networks

Broadcast Networks is the mainly used OSPF Network Type. It uses Multicast and Broadcast to reach multi endpoints. This is a very useful network topology for an OSPF design.

 

DR and BDR selection is done for Broadcast Networks.

 

 

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OSPF Network Types: Nonbroadcast Multi Access(NBMA) Networks

Nonbroadcast Multi Access(NBMA) Networks is basically an simulation of Broadcast Networks. Each neighbour connect eachother as unicast and all Open Shortest Path First packets are Unicast.

 

OSPF DR and BDR selection is done for Nonbroadcast Multi Access(NBMA) Networks.

 

 

As we can understand from its name, Point-to-Point Network is one of the OSPF Network Types that provides connection from one end to another end. There are two nodes and the communication is between these nodes for a single Point-to-Point connection.

 

OSPF DR and BDR selection is not necessary for Point-to-Point OSPF Networks and so it is not takes place.

 

 

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Point-to-Multipoint OSPF Networks

This is a special NBMA (Non Broadcast Multi Access) network. All network is consist of Point-to-Point links. All OSPF packets are Multicast.

 

OSPF DR and BDR selection is not necessary for Point-to-Multipoint OSPF Networks and so it is not takes place.

 

 

Point-to-Multipoint Non Broadcast Networks

Point-to-Multipoint Non Broadcast Networks are the networks that has multiple end points but is not Broadcast capable. So, individual virtual circuits (PVCs) are created between the end points.

Here, we have talked about OSPF Network Types one by one. We have learned Point-to-Point, Point-to-Multipoint, Point-to-Multipoint Non Broadcast, Broadcast and NBMA OSPF Networks. Each of these types are used in different scenarious and for different network topologies. You can use the below OSPF Network Types summary shape, as a reminder for you.

 

 

In the next article, we will focus on the remainning Open Shortest Path First lessons. One of them is “Virtual Links”. Keep on…