LevelOne GTL-2691 - Manual (Page 1526)

C HAPTER 49 | IP Routing Commands
Open Shortest Path First (OSPFv3)
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no-summary - Stops an Area Border Router (ABR) from sending
summary link advertisements into the stub area.
C OMMAND M ODE
Router Configuration
D EFAULT S ETTING
No stub is configured.
Summary advertisement are sent into the stub.
C OMMAND U SAGE
◆ All routers in a stub must be configured with the same area ID.
◆ Routing table space is saved by stopping an ABR from flooding Type-4
Inter-Area Router and Type 5 AS-External LSAs into the stub. Since no
information on external routes is known inside the stub, an ABR will
advertise the default route 0::0/0 using a Type 3 Inter-Area Prefix LSA.
◆ The default setting for this command blocks Type-4 Inter-Area Router
and Type 5 AS-External LSAs. Therefore, any destinations that cannot
be matched to an inter-area or intra-area route will have to use the
default route.
◆ Use the no-summary parameter of this command on an ABR attached
to the stub to define a totally stubby area, blocking all Type 3 network
summary LSAs. Define an area as a totally stubby area only if routers
in the area do not require summary LSAs from other areas.
◆ Use the area default-cost command to specify the cost of a default
summary route sent into a stub by an ABR attached to the stub area.
E XAMPLE
This example creates a stub area 2, and makes it totally stubby by blocking
all Type 3 summary LSAs.
Console(config-router)#area 2 stub no-summary
Console(config-router)#
R ELATED C OMMANDS
area default-cost (1522)