GS-5220-Series (V4) User Manual

Table Of Contents
Users Manual of GS-5220 PoE Series Managed Switch
267
4.4.4.8 Virtual Link
All OSPF areas must connect to the backbone. If an area does not have a direct physical connection to the backbone, you can
configure a virtual link that provides a logical path to the backbone. To connect an isolated area to the backbone, the logical
path can cross a single nonbackbone area to reach the backbone. To define the path, you must specify one endpoint on the
ABR that connects the isolated area to the common nonbackbone area, and the other endpoint on the ABR that connects this
common nonbackbone area and the backbone itself. (However, note that you cannot configure a virtual link that runs through a
stub or NSSA area.)
Virtual links can also be used to create a redundant link between any area and the backbone to help prevent partitioning, or to
connect two existing backbone areas into a common backbone.
To configure a virtual link, specify the transit area through which the endpoint routers connect, and the address of the router on
this side of the link.
Following is OSPF virtual link configuration table. The virtual link is established between 2 ABRs to overcome that all the areas
have to be connected directly to the backbone area. The screen in Figure 4-4-4-8 appears.
Figure 4-4-4-8: Virtual Link Page Screenshot
The page includes the following fields:
Object Description
Area ID OSPF Area ID.
Router ID OSPF router ID.