Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 169)

Brocade Virtual ADX Switch and Router Guide 155
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Enabling OSPFv3
7
As the NSSA is partially “stubby”, the ABR does not flood external LSAs from the backbone into the
NSSA. To provide access to the rest of the Autonomous System (AS), the ABR generates a default
Type 7 LSA into the NSSA.
Configuring an NSSA
Using the area area-id nssa command, you can block the generation of Type 3 and Type 7 LSAs into
an NSSA. This command also provides an option to configure the NSSA translator role.
Configuration examples
The following example creates an NSSA area with the area ID 100. If the router is an ABR, then a
Type 3 summary LSA is originated into the NSSA and if the router is an ASBR then a Type 7 NSSA
external LSA is generated into the NSSA, with a default external metric value of 10. The router’s
NSSA translator role is set to candidate and it participates in the NSSA translation election.
Virtual ADX(config-ospf6-router)# area 100 nssa
The following example modifies the area 100 of the NSSA so that a Type 7 NSSA external LSA is not
originated into the area of the NSSA. The Type 3 summary LSAs are still originated into the area of
the NSSAs.
Virtual ADX(config-ospf6-router)# area 100 nssa no-redistribution
The following example modifies the area 100 of the NSSA so that the origination of Type 3
summary LSAs (apart from the Type 3 default summary) is blocked into NSSA area. The CLI works
in incremental fashion and the origination of the Type 7 LSA continue to be blocked as
no-redistribution was enabled in the previous command.
Virtual ADX(config-ospf6-router)#area 100 nssa no-summary
The following example modifies the area 100 of the NSSA so that the origination of Type 3
summary is allowed, but the origination of Type 7 LSA is blocked. Also, the self-router still act as the
NSSA translator-always option in the following example:
Virtual ADX(config-ospf6-router)#no area 100 nssa no-summary
Virtual ADX(config-ospf6-router)#area 100 nssa no-redistribution
translator-always
Although the NSSA can be configured in an incremental fashion using show run, all the
configuration options is displayed in just one line.
The following example deletes the area 100 of the NSSA :
Virtual ADX(config-ospf6-router)#no area 100
Syntax: [no] area area-id nssa [[stub-metric ] [default-information-originate] [no-summary]
[no-redistribution]]
The area-id parameter specifies the area number, which can be a number or in IP address format.
If you specify a number, the number can be from 0 through 2,147,483,647.
The nssa stub-metric parameter configures an area as a NSSA. The stub-metric variable is the
metric used for generating the default LSA in an NSSA. The value ranges from 1 through
1,048,575. The default value is 10.
The default-information-originate parameter generates a default route into an NSSA. If no-summary
is enabled then a Type 3 default LSA is generated into the NSSA, or a Type 7 LSA is generated into
the NSSA. By default, the default-information-origiante parameter is not set.
The no-summary parameter prevents an NSSA ABR from generating a Type 3 summary into an
NSSA. By default, the summary LSA is originated into NSSA.