User guide

B
LACK
D
IAMOND
U
SER
G
UIDE
9-7
O
VERVIEW OF
OSPF
Figure 9-1:
Stub area
V
IRTUAL
L
INKS
In the situation when a new area is introduced that does have a direct physical
attachment to the backbone, a virtual link is used. A virtual link provides a logical path
between the ABR of the disconnected area and the ABR of the backbone. A virtual link
must be established between two ABRs that have a common area, with one ABR
connected to the backbone. Figure 9-2 illustrates a virtual link.
ABR
Stub
Area
Area 0
BD_012
MSM
1234AB5678
MSM
G6X G6X
F32T
F32T
F32T
G4X
G4X
G4X