Configuring a manual virtual interface

Use manual virtual links (interfaces) to provide a backup link for vital OSPF traffic with a minimum of resource use.

Before you begin

Enable OSPF globally.
Change the VRF instance as required to configure OSPF on a specific VRF instance. The VRF must have an RP trigger of OSPF. Not all parameters are configurable on non-default VRFs.

Procedure

In the navigation pane, expand Configuration > IP.
Click OSPF.
Click the Virtual If tab.
Click Insert.
Specify the area ID of the transit area.

The transit area is the common area between two ABRs.
Specify the neighbor ID.

The neighbor ID is the IP router ID of the ABR that the other ABR needs to reach the backbone.
Click Insert.
To verify that the virtual link is active, click Refresh and check the State column.

If the state is point-to-point, the virtual link is active. If the state is down, the virtual link configuration is incorrect.

Virtual If field descriptions

Use the data in the following table to use the Virtual If tab.


Name	Description
AreaId	Specifies the transit area ID that the virtual link traverses.
Neighbor	Specifies the router ID of the virtual neighbor.
TransitDelay	Specifies the estimated number of seconds required to transmit a link-state update packet over this interface. The default is 1.
RetransInterval	Specifies the number of seconds between link-state advertisement, and retransmissions for adjacencies that belong to this interface. This variable also applies to DD and link-state request packets. This value must exceed the expected round-trip time. The default is 5.
HelloInterval	Specifies the length of time, in seconds, between the hello packets that the router sends on the interface. This value must be the same for the virtual neighbor. The default is 10.
RtrDeadInterval	Specifies the number of seconds that expires before neighbors declare the router down. This value must be a multiple of the hello interval. This value must be the same for the virtual neighbor. The default is 60.
State	Specifies the OSPF virtual interface state.
Events	Specifies the number of state changes or error events on this virtual Link.
AuthType	Specifies the authentication type specified for a virtual interface. You can locally assign additional authentication types. The default is none.
AuthKey	Specifies the authentication password. If AuthType is a simple password, the device adjusts and zeros fill the eight octets. Unauthenticated interfaces need no authentication key, and simple password authentication cannot use a key with more than eight octets.
LsaCount	Specifies the total number of link state advertisements in this virtual interface LSDB.
LsaCksumSum	Specifies the number of link-state advertisements. The sum determines if a change occurred in a virtual interface LSDB and compares the virtual interfaceLSDB of the virtual neighbors.