nssa (OSPFv3 Area)

Function

The nssa command configures an OSPFv3 area as an NSSA.

The undo nssa command cancels the configuration.

By default, no OSPFv3 area is configured as an NSSA.

Format

undo nssa

Parameters

Parameter	Description	Value
default-route-advertise	Generates default Type7 LSAs on the ASBR and then advertises them to the NSSA. NOTE: The ABR generates a default NSSA LSA (Type7 LSA) automatically and advertises it in the NSSA.	-
cost cost	Specifies the default cost of Type 7 LSAs.	It is an integer ranging from 1 to 16777214. The default value is 1.
type type	Specifies the type of the external routes.	The value is an integer ranging from 1 to 2. By default, it is 2. 1: Type 1 external route 2: Type 2 external route
tag tag	Specifies the tag value of the OSPFv3 route imported to an NSSA.	It is an integer ranging from 0 to 4294967295. The default value is 0.
no-import-route	Indicates that no external routes are imported to NSSAs.	-
no-summary	Disables ABRs from sending summary LSAs to NSSAs.	-
translator-always	Specifies the ABR in an NSSA as the translator. Multiple ABRs in an NSSA can be configured as translators.	-
translator-interval translator-interval	Specifies the timeout period of a translator.	It is an integer ranging from 1 to 120, in seconds. The default value is 40 seconds.
set-n-bit	Indicates that the N-bit is set in DD packets.	-
suppress-forwarding-address	Enables the device to suppress the forwarding address of a Type 5 LSA translated from a Type 7 LSA.	-

Views

OSPFv3 area view

Default Level

2: Configuration level

Usage Guidelines

If an area is configured to the nssa area, all switches of the area must be configured with the NSSA attribute.

The area will be updated after NSSA attributes are configured or deleted. Thus, the NSSA attributes can be re-configured or deleted only after the last update of NSSA attributes is complete.

The keyword default-route-advertise is used to generate default Type 7 LSAs. Regardless of whether there is route ::/0 in the routing table on an ABR, a Type 7 LSA default route is generated. A Type 7 LSA default route can be generated only when there is route ::/0 in the routing table on an ASBR.

When an ASBR is also an ABR, you can specify no-import-route to disable OSPFv3 from advertising the external routes imported through the import-route command to NSSAs. To reduce the number of LSAs to be transmitted to NSSAs, you can specify no-summary on an ABR to disable the ABR from transmitting summary LSAs (Type 3 LSAs) to NSSAs.

When the LS age field (aging time) in the LSA header reaches 3600 seconds, this LSA is deleted.
After the keyword set-n-bit is set, a switch re-establishes neighbor relationships with switches directly connected to it in the NSSA.

Example

# Configure Area 1 as an NSSA, and set the timeout period of the translator to 20s.

<HUAWEI> system-view
[HUAWEI] ospfv3 1
[HUAWEI-ospfv3-1] area 1
[HUAWEI-ospfv3-1-area-0.0.0.1] nssa translator-interval 20