Syntax: [no] area { num | ip-addr nssa cost [ no-summary ] | default-information-originate }
The num and ip-addr parameters specify the area number, which can be a number or in IP address format. If you specify a number, the
number can be from 0 - 2,147,483,647.
The nssa cost and default-information-originate parameters specify that this is a Not-So-Stubby-Area (NSSA). The cost species an
additional cost for using a route to or from this NSSA and can be from 1 - 16777215. There is no default. Normal areas do not use the
cost parameter. Alternatively, you can use the default-information-originate parameter causes the device to inject the default route into
the NSSA.
Specifying the no-summary option directs the router to not import type 3 summary LSAs into the NSSA area. The default operation is to
import summary LSAs into an NSSA area.
NOTE
The device does not inject the default route into an NSSA by default.
To congure additional parameters for OSPF interfaces in the NSSA, use the ip ospf area command at the interface level of the CLI.
Disabling the router to perform translations for NSSA LSAs
The no nssa-translator command allows you to disable the router to perform translations for NSSA LSAs. When this command is used,
type 7 NSSA external LSAs are not translated into type 5 external LSAs. This command is useful when the router is an area border router
with many NSSA areas, and does not need to export the NSSA external routes into the backbone.
The following command enables this feature.
device(config)# router ospf
device(config-ospf-router)# no nssa-translator
Syntax: [no] nssa-translator
Conguring an address range for the NSSA
If you want the ABR that connects the NSSA to other areas to summarize the routes in the NSSA before translating them into Type-5
LSAs and ooding them into the other areas, congure an address range. The ABR creates an aggregate value based on the address
range. The aggregate value becomes the address that the ABR advertises instead of advertising the individual addresses represented by
the aggregate. You can congure up to 32 ranges in an OSPF area.
To congure an address range in NSSA 1.1.1.1, enter the following commands. This example assumes that you have already congured
NSSA 1.1.1.1.
device(config)# router ospf
device(config-ospf-router)# area 1.1.1.1 range 209.157.22.1 255.255.0.0
device(config-ospf-router)# write memory
Syntax: [no] area { num | ip-addr range ip-addr ip-mask [ advertise | not-advertise ] }
The num and ip-addr parameters specify the area number, which can be in IP address format. If you specify a number, the number can
be from 0 - 2,147,483,647.
The range ip-addr parameter
species the IP address portion of the range. The software compares the address with the signicant bits in
the mask. All network addresses that match this comparison are summarized in a single route advertised by the router.
The ip-mask parameter species the portions of the IP address that a route must contain to be summarized in the summary route. In the
example above, all networks that begin with 209.157 are summarized into a single route.
The advertise and not-advertise parameters specify whether you want the device to send type 3 LSAs for the specied range in this
area. The default is advertise .
Conguring OSPF
FastIron Ethernet Switch Layer 3 Routing
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