| When configuring the network type for OSPF deployment, the following options are available. config router ospf config ospf-interface edit 1 set interface "port1" set network-type ? broadcast Broadcast.
non-broadcast Non-broadcast.
point-to-point Point-to-point.
point-to-multipoint Point-to-multipoint.
point-to-multipoint-non-broadcast Point-to-multipoint and non-broadcast. Below is a brief explanation for each of them. -
Broadcast: - Default for Ethernet networks.
- Supports automatic neighbor discovery.
- Uses multicast to send updates to all OSPF routers on the network.
-
Non-Broadcast: - Used in networks that do not support broadcast.
- Requires manual configuration of neighbors.
- Does not use multicast; instead, it sends updates directly to each neighbor.
- Commonly used in NBMA networks, where explicit neighbor configuration ensures reliable OSPF communication.
-
Point-to-Point: - Used for direct connections between two routers.
- Simplifies configuration as there are only two endpoints.
- Automatically discovers the neighbor.
- Reduces OSPF overhead since no DR/BDR election is needed on a two-router link.
-
Point-to-Multipoint: - Used in networks where a single interface connects to multiple routers.
- Treats the network as a series of point-to-point links.
- Can be configured with or without broadcast capability.
- Useful in hub-and-spoke designs because it avoids DR elections and treats each spoke independently.
For network types that support broadcast, Designated Router (DR) and Backup Designated Router (BDR) elections are happening. This applies to both broadcast and point-to-multipoint (broadcast) OSPF network types. Refer to the OSPF command output, which will be either of the following, depending on the role of the FortiGate. get router info ospf neighbor
OSPF process 0:
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 1 Full/ DR 00:00:32 10.10.10.2 port10
2.2.2.2 1 Full/ BDR 00:00:32 10.20.20.2 port1 1.1.1.1 1 Full/ DROTHER 00:00:32 10.20.20.2 port4 get router info ospf interfac
port1 is up, line protocol is up
Internet Address 10.5.28.246/20, Area 0.0.0.0, MTU 1500
Process ID 0, VRF 0, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1 For the OSPF network type 'point-to-point', there is no DR and BDR election. Hence, the output will be as follows. get router info ospf neighbor
OSPF process 0:
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 1 Full/ - 00:00:32 10.10.10.2 port10
2.2.2.2 1 Full/ - 00:00:32 10.20.20.2 port1 1.1.1.1 1 Full/ - 00:00:32 10.20.20.5 port4 get router info ospf interface
port1 is up, line protocol is up
Internet Address 10.5.28.246/20, Area 0.0.0.0, MTU 1500
Process ID 0, VRF 0, Router ID 1.1.1.1, Network Type POINT-TO-POINT, Cost: 1 Related documents: Technical Tip: OSPF Resource List Technical Tip: Understanding OSPF States Basic OSPF example | 
