area stub
area virtual-link
Copyright © 2010, Juniper Networks, Inc.
NOTE: We recommend that you do not use the
default-information-originate keyword with the no-summary keyword for
an NSSA.
Example
host1(config-router)#area 35.0.0.0 nssa
Use the no version to remove the NSSA designation from the area, to stop the
generation of type 7 default LSAs, to reinitiate type 3 summary LSAs into the area (with
the no-summary keyword), or to stop the application of the specified metric cost,
metric type, or a route map to the type 7 default LSAs.
See area nssa
Use to configure a stub area. Stub areas do not get flooded with external LSAs but do
carry a default route, intra-area routes, and interarea routes. The lack of flooding in
stub areas reduces the size of the OSPF database for the area and decreases memory
usage for external routers in the stub area.
You must configure each router in a stub area as belonging to the stub area.
You cannot configure virtual links across a stub area.
Stub areas cannot contain AS boundary routers.
Use the no-summary keyword to create a "totally stubby area" and restrict type 3
summary LSAs from entering the stub area. However, type 3 default-route LSAs can
continue to flow into the area.
Example
host1(config-router)#area 47.0.0.0 stub
Use the no version to disable this function.
See area stub
Use to configure an OSPF virtual link.
A virtual link is used for areas that do not have a direct connection to the backbone
area.
To have configured virtual links, the router itself must be an ABR.
Virtual links are identified by the router ID of the other endpoint, which is also an ABR.
The two endpoint routers must be attached to a common area, called the virtual link's
transit area.
Virtual links are part of the backbone and behave as if they were unnumbered
point-to-point networks between the two routers.
Chapter 5: Configuring OSPF
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