3Com 4007, Implementation Manual, Page: 489 / 684

Virtual Links 489
The endpoints of a virtual link must be area border routers. You must
configure the virtual link on both routers. Each router’s virtual link
definition includes the other router’s router ID and the transit area
through which the routers connect. Figure 55 illustrates a virtual link
between two area border routers.
Figure 55 Virtual Link
In Figure 55, area 0.0.0.1 cannot be physically connected to the
backbone area. Instead, connectivity to the backbone is achieved using a
virtual link, configured between router A and router B. Area 0.0.0.2 is the
transit area, and router B is the entry point into backbone area 0.0.0.0.
The virtual link in Figure 55 provides area 0.0.0.1 and router A with a
logical connection to the backbone. Here is the virtual link configuration
for both routers shown in Figure 55:
■
Router A:
■
Transit area: 0.0.0.2
■
Target router: 3.1.1.1
■
Router B:
■
Transit area: 0.0.0.2
■
Target router: 2.1.1.1
Backbone
area 0.0.0.0
Router A
(Router ID: 2.1.1.1)
Virtual link
Router B
(Router ID: 3.1.1.1)
Area 0.0.0.1
Area 0.0.0.2
L3
L3