Configuring NBMA Network Attributes

Procedure

(Optional) Set the network type to NBMA.

An NBMA network must be fully meshed. That is, any two switches on an NBMA network must be directly reachable. In most cases, however, this is not true. To resolve this problem, you can run specific commands to forcibly change the network type to NBMA. For details, see Configuring Network Types for OSPF Interfaces.
1. Run system-view
  
  The system view is displayed.
2. Run interface interface-type interface-number
  
  The interface view is displayed.
3. (Optional) On an Ethernet interface, run undo portswitch
  The interface is switched to Layer 3 mode.
  
  By default, an Ethernet interface works in Layer 2 mode.
  
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
4. Run ospf network-type nbma
  
  The network type of the OSPF interface is set to NBMA.
(Optional) Set the interval at which Hello packets for polling are sent on the NBMA network.

On the NBMA network, after the neighbor relationship becomes invalid, the switch sends Hello packets at an interval defined in the polling mechanism.
1. Run ospf timer poll interval
  
  The interval at which Hello packets for polling are sent is set on an NBMA interface.
  
  The default value is 120, in seconds.
Configure a neighboring switch on the NBMA network.

If the network type of an interface is NBMA, the interface cannot broadcast Hello packets to discover neighboring switches. Therefore, the IP address of a neighboring switch and whether the neighboring switch can participate in DR election must be configured manually on the interface.
1. Run quit
  
  Exit the interface view.
2. Run ospf [ process-id ]
  
  The OSPF process view is displayed.
3. Run peer ip-address [ dr-priority priority ]
  
  A neighboring switch is configured on the NBMA network.