3Com Switch 8800 Configuration Guide Chapter 19 OSPF Configuration19-24Table 19-27 Configure an OSPF virtual linkOperation CommandCreate and configure a virtuallinkvlink-peer router-id [ hello seconds | retransmitseconds | trans-delay seconds | dead seconds |simple password | md5 keyid key ]*Remove the created virtual link undo vlink-peer router-idarea-id and router-id have no default value. By default, hello timer is 10 seconds,retransmit 5 seconds, trans-delay 1 second, and the dead 40 seconds.19.2.21 Configuring Stub Area of OSPFStub areas are some special areas, in which the ABRs do not propagate the learnedexternal routes of the AS.The stub area is an optional configuration attribute, but not every area conforms to theconfiguration condition. Generally, stub areas, located at the AS boundaries, are thosenon-backbone areas with only one ABR. Even if this area has multiple ABRs, no virtuallinks are established between these ABRs.To ensure that the routes to the destinations outside the AS are still reachable, the ABRin this area will generate a default route (0.0.0.0) and advertise it to the non-ABRrouters in the area.Pay attention to the following items when configuring a stub area:z The backbone area cannot be configured to be the stub area and the virtual linkcannot pass through the stub area.z If you want to configure an area to be the stub area, then all the routers in this areashould be configured with this attribute.z No ASBR can exist in a stub area. In other words, the external routes of the AScannot be propagated in the stub area.Perform the following configuration in OSPF area view.
