Virtual Link - Hirschmann MACH 4000 User Manual

OSPF

7.1.4 Virtual Link

OSPF requires that the backbone area can be passed through. However, if
this is not actually possible, then OSPF provides a virtual link (VL) to connect
parts of the backbone area with each other
you to connect an area that is connected with the backbone area via another
area.
Backbone Area 0
Figure 27: Linking a remote area to the backbone area with a virtual link (VL)
Backbone Area 0
Figure 28: Expanding the backbone area with a virtual link (VL)
Routing L3P
Release 4.0 11/07
Area 1
VL
ABR
Router 2
Router-ID:
2.2.2.2
Area 1
VL
ABR
7.1 OSPF-Topology
(see fig. 28). A VL even allows
Area 2
ABR
Router 1
Router-ID:
1.1.1.1
Backbone Area 0
ABR
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