nssa (OSPF area view)

Use nssa to configure an area as an NSSA area.

Use undo nssa to restore the default.

Syntax

nssa [ default-route-advertise [ cost cost-value | nssa-only | route-policy route-policy-name | type type ] * | no-import-route | no-summary | suppress-fa | [ [ [ translate-always ] [ translate-ignore-checking-backbone ] ] | translate-never ] | translator-stability-interval value ] *

undo nssa [ default-route-advertise [ cost | nssa-only | route-policy | type ] * | no-import-route | no-summary | suppress-fa | [ translate-always | translate-never ] | translator-stability-interval ] *

Default

No area is configured as an NSSA area.

Views

OSPF area view

Predefined user roles

network-admin

Parameters

default-route-advertise: Used on an NSSA ABR or an ASBR only. With this keyword, an NSSA ABR redistributes a default route in a Type-7 LSA into the NSSA area. The ABR redistributes a default route regardless of whether a default route exists in the routing table. With this keyword, an ASBR redistributes a default route in a Type-7 LSA only when the default route exists in the routing table.

cost cost-value: Specifies a cost for the default route, in the range of 0 to 16777214. If you do not specify this option, the default cost specified by the default-cost command applies.

nssa-only: Limits the default route advertisement to the NSSA area by setting the P-bit of Type-7 LSAs to 0. By default, the P-bit of Type-7 LSAs is set to 1. If the router acts as both an ASBR and an ABR and FULL state neighbors exist in the backbone area, the P-bit is set to 0.

route-policy route-policy-name: Specifies a routing policy by its name, a case-sensitive string of 1 to 63 characters. When a default route exists in the routing table and the routing policy is matched, the command redistributes a default route in a Type-7 LSA into the OSPF routing domain. The routing policy modifies values in the Type-7 LSA.

type type: Specifies a type for the Type-7 LSA, 1 or 2. If you do not specify this option, the default type specified by the default type command applies.

no-import-route: Used on an NSSA ABR to control the import-route command to not redistribute routes into the NSSA area.

no-summary: Used only on an ABR to advertise a default route in a Type-3 summary LSA into the NSSA area and to not advertise other summary LSAs into the area. The area is a totally NSSA area.

suppress-fa: Suppresses the forwarding address in the Type-7 LSAs from being placed in the Type-5 LSAs.

translate-always: Always translates Type-7 LSAs to Type-5 LSAs. This keyword takes effect only on an NSSA ABR.

translate-ignore-checking-backbone: Ignores checking for FULL state neighbors in the backbone area during the translator election in the NSSA area.

translate-never: Never translates Type-7 LSAs to Type-5 LSAs. This keyword takes effect only on an NSSA ABR.

translator-stability-interval value: Specifies the stability interval of the translator. During the interval, the translator can maintain its translating capability after another device becomes the new translator. The value argument is the stability interval in the range of 0 to 900 seconds and defaults to 0. A value of 0 means the translator does not maintain its translating capability when a new translator arises.

Usage guidelines

All routers attached to an NSSA area must be configured with the nssa command in area view.

If you specify the translate-ignore-checking-backbone keyword for an ABR, you must also specify the keyword for other ABRs in the NSSA area. This ensures that a translator can be elected among the ABRs.

Examples

# Configure Area 1 as an NSSA area.

<Sysname> system-view
[Sysname] ospf 100
[Sysname-ospf-100] area 1
[Sysname-ospf-100-area-0.0.0.1] nssa

Related commands

default-cost (OSPF area view)