Configuring the Network Segments Included by Each Area
The interface running OSPF can normally receive and send OSPF packets only when the network segments included by each area are correctly configured.
Context
Network segments mentioned in this section refer to the network segments where interfaces running OSPF reside.
A network segment can belong to only one area. In other words, you need to specify an area for each interface running OSPF.
Most configurations should be based on the area. Wrong configuration may disable information transmission between the neighboring routers, and even lead to congestion or self-loop of the routing information.
Procedure
- Access the system view.
- Access the OSPF process view.
ospf [ process-id ]
- Access the OSPF area view.
area area-id
- Specify network segments for this area.
network ip-address wildcard-mask
OSPF can run on an interface only when the following conditions are satisfied:
- Mask length of the IP address of an interface is not shorter than that in the network command.
When the wildcard-mask parameter in the network command is specified as 0, if the IP address of the interface and the IP address that is configured by the network address command are the same, OSPF is enabled on the interface.
- Master IP address of an interface must belong to the network segment specified by the network command.
The address segment of the MPU management interface GigabitEthernet 0/0/0 cannot be released to the OSPF area through the network command.
For a loopback interface, by default, OSPF advertises its IP address in 32-bit host route, regardless of the mask length of the IP address on the interface. To advertise the segment route of the loopback interface, configure the network type as NBMA or broadcast in the interface view.
- Mask length of the IP address of an interface is not shorter than that in the network command.