OSPF NETWORK TYPES
There are five different network types within which OSPF operates.
The following list explains the characteristics of the OSPF network types:
Broadcast
- 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.
Non-Broadcast
- 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
Point-to-Point
- 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.
Point-to-Multipoint
- 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.
To summarize , we can enumerate the OSPF Network Types in the below table –
