HP 3500YL - Manual (Page 263)

IP Routing Features
Configuring OSPF
Configuring a Virtual Link
Syntax: ip ospf area < area-id > virtual-link < ip-address>
Used on a pair of ABRs at opposite ends of a virtual link in
the same area to configure the virtual link connection.
< area-id >: This must be the same for both ABRs in the link,
and is the area number of the virtual link transit area in either
decimal or dotted decimal format.
< ip-address >: On an ABR directly connected to the backbone
area, this value must be the IP address of an ABR (in the same
area) needing a virtual link to the backbone area as a
substitute for a direct physical connection. On the ABR that
needs the virtual link to the backbone area, this value must be
the IP address of the ABR (in the same area) having a direct
physical connection to the backbone area.
Example. Figure 5-34 shows an OSPF ABR, routing switch “A”, that lacks a
direct connection to the backbone area (area 0). To provide backbone access
to routing switch “A”, you can add a virtual link between routing switch “A”
and routing switch “C”, using area 1 as a transit area. To configure the virtual
link, define it on the routers that are at each end of the link. No configuration
for the virtual link is required on the other routers on the path through the
transit area (such as routing switch “B” in this example).
OSPF Area 0
OSPF Area 1
“transit area” OSPF Area 2
ProCurve 8212zl “B” ProCurve 8212zl “A”
Router ID 10.0.0.1
ProCurve8212zl “C”
Router ID 209.157.22.1
Figure 5-34. Defining OSPF virtual links within a network
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