Configuring Network Types of OSPF Interfaces
Context
By default, the physical interface type determines the network type.
- The network type of an Ethernet interface is broadcast.
- The network type of a serial interface running PPP or HDLC is P2P.
- The network type of an ATM interface or a frame relay (FR) interface is NBMA.
- A P2MP network is forcibly changed from another other type of network.
- AR100&AR120&AR150&AR160&AR200 series do not support frame-relay interface.
The network types of the interfaces on both ends of a link must be the same; otherwise, the OSPF neighbor relationship cannot be established.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The OSPF interface view is displayed.
- Run ospf network-type { broadcast | nbma | p2mp | p2p [ peer-ip-ignore ] }
The network type of the OSPF interface is configured.
By default, the network type of an interface depends on the physical interface. The network type of an Ethernet interface is broadcast; the network type of a serial or POS interface (encapsulated with PPP or HDLC) is P2P; the network type of an ATM and FR interface is NBMA.
When the network type is configured for an interface, the original network type of the interface is replaced.
The network type can be configured to suit networking requirements.- If the network type of an interface is broadcast and a router does not support multicast addresses, change the network type of the interface to NBMA.
- If the network type of an interface is NBMA and the network is fully meshed or any two routers are directly connected, change the network type of the interface to broadcast and do not configure neighboring router information on the interface.
- If the network type of an interface is NBMA and the network is not fully meshed, change the network type of the interface to P2MP. After that, two indirectly connected routers can communicate through one router that can directly reach both the two routers. After the network type of the interface is changed to P2MP, configuring neighboring router information on the interface is unnecessary.
- If only two routers run OSPF on the same network segment, changing the network type of the interface to P2P is recommended.
OSPF cannot be configured on a null interface.