H3C Technologies H3C SecPath F1000-E - Manual (Page 422)

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NOTE:
•
You are required to use the stub command on routers attached to a stub area.
• Using the default-cost command only takes effect on the ABR of a stub area.
• The backbone area cannot be a (totally) stub area.
• A (totally) stub area cannot have an ASBR because AS external routes cannot be distributed into the stub
area.
• Virtual links cannot transit (totally) stub areas.
Configuring an NSSA area
A stub area cannot redistribute routes. You can configure the area as an NSSA area to allow for route
redistribution by keeping other stub area characteristics.
To configure an NSSA area:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter OSPF view.
ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ] *
N/A
3. Enter area view. area area-id N/A
4. Configure the area as an NSSA
area.
nssa [ default-route-advertise |
no-import-route | no-summary |
translate-always |
translator-stability-interval value ] *
Not configured by default.
5. Specify a cost for the default
route advertised to the NSSA
area.
default-cost cost
Optional.
Defaults to 1.
NOTE:
•
You are required to use the nssa command on all the routers attached to an NSSA area.
• The default-cost command is available only on the ABR/ASBR of an NSSA area.
Configuring a virtual link
Non-backbone areas exchange routing information through the backbone area. Connectivity between
the backbone and non-backbone areas and within the backbone must be maintained.
If necessary physical links are not available for this connectivity maintenance, you can configure virtual
links to solve it.
To configure a virtual link:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter OSPF view.
ospf [ process-id | router-id router-id
| vpn-instance vpn-instance-name ] *
N/A
3. Enter area view. area area-id N/A