Edge-Core ECS4660-28F, Management Manual, Page: 1764 / 2020

C
HAPTER
51
| IP Routing Commands
Open Shortest Path First (OSPFv2)
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E
XAMPLE
This example creates a stub area 10.3.0.0, and assigns all interfaces with
class B addresses 10.3.x.x to the NSSA. It also instructs the router to
generate external LSAs into the NSSA when it is an NSSA ABR or NSSA
ASBR.
Console(config-router)#area 10.3.0.0 nssa default-information-originate
Console(config-router)#network 10.3.0.0 255.255.0.0 area 10.2.0.0
Console(config-router)#
area stub
This command defines a stub area. To remove a stub, use the no form
without the optional keyword. To remove the summary attribute, use the
no form with the summary keyword.
S
YNTAX
[ no ] area area-id stub [ no-summary ]
area-id - Identifies the stub area. The area ID can be in the form of
an IPv4 address or as a four octet unsigned integer ranging from
0-4294967295.
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 in a stub by blocking Type-4 AS summary
LSAs and Type 5 external LSAs. The default setting for this command
completely isolates the stub by blocking Type-3 summary LSAs that
advertise the default route for destinations external to the local area or
the autonomous system.
◆
Use the no-summary parameter of this command on the ABR attached
to the stub to define a totally stubby area. 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.