3Com Switch 8800 Advanced Software V5 Configuration Guide

Configuring OSPFv3 Area Parameters 357
■ When configuring a router ID, make sure each router has a unique ID. If a
router runs multiple OSPFv3 processes, you need to specify a router ID for each
process.
Configuring OSPFv3
Area Parameters
The stub area and virtual link support of OSPFv3 has the same principle and
application environments with OSPFv2.
Splitting an OSPFv3 AS into multiple areas reduces the number of LSAs on
networks and extends OSPFv3 application. For those non-backbone areas residing
on the AS boundary, you can configure them as Stub areas to further reduce the
size of routing tables on routers in these areas and the number of LSAs.
Non-backbone areas exchange routing information via the backbone area.
Therefore, the backbone and non-backbone areas, including the backbone itself
must maintain connectivity. In practice, necessary physical links may not be
available for connectivity. You can configure virtual links to address it.
Prerequisites ■ Enable IPv6 packet forwarding
■ Configure OSPFv3 basic functions
Configuring an OSPFv3
Stub Area
To configure an OSPFv3 stub area, use the following commands:
n
■ Configurations on routers attached to the same area should be compatible to
avoid information exchange failures, information block and routing loops.
■ You cannot delete an OSPFv3 area directly. Only when you remove all
configurations in area view and all interfaces attached to the area become
down, can the area be removed automatically.
■ All routers attached to a stub area must be configured with the stub
command. The keyword no-summary is only available on the ABR.
■ If you use the stub command with the keyword no-summary on an ABR, the
ABR distributes a default summary LSA into the area rather than generating an
AS-external-LSA or Inter-Area-Prefix-LSA. The stub area of this kind is also
known as totally stub area.
Configuring OSPFv3
Virtual Links
You can configure virtual links to maintain connectivity between non-backbone
areas and the backbone, or in the backbone itself.
To configure a virtual link, use the following commands:
To do... Use the command... Remarks
Enter system view system-view -
Enter OSPFv3 view ospfv3 [ process-id ] -
Enter OSPFv3 area view area area-id -
Configure the area as a
stub area
stub [ no-summary ] Required
Not configured by default
Configure the default
route cost of sending a
packet to the stub area
default-cost value Optional
Defaults to 1