286
NOTE:
•
You cannot remove an OSPFv3 area directly. The area can be removed only when you remove all
configurations in area view and all interfaces attached to the area become down.
•
All the routers attached to a stub area must be configured with the
stub
command. The keyword
no-summary
is only available on the ABR of the stub area.
•
If you use the
stub
command with the keyword
no-summary
on an ABR, the ABR advertises a default
route in an Inter-Area-Prefix-LSA into the stub area. No AS-external-LSA, Inter-Area-Prefix-LSA, or
Inter-Area-Router-LSA is advertised in the area. The stub area of this kind is also known as a “totally stub
area.”
Configuring an OSPFv3 virtual link
You can configure a virtual link to maintain connectivity between a non-backbone area and the
backbone, or in the backbone itself.
Follow these steps to configure a virtual link:
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 a virtual link
vlink-peer
router-id
[
hello
seconds
|
retransmit
seconds
|
trans-delay
seconds
|
dead
seconds
|
instance
instance-id
] *
Required
NOTE:
•
Both ends of a virtual link are ABRs that must be configured with the
vlink-peer
command.
•
Do not configure virtual links in the areas of a GR-capable process.
Configuring OSPFv3 network types
OSPFv3 classifies networks into the following types by the link layer protocol.
By default, the default OSPFv3 interface network types vary with the link layer protocols of the interfaces:
•
When the link layer protocol is PPP, OSPFv3 considers the network type as P2P by default.
•
When the link layer protocol is Ethernet, OSPFv3 considers the network type as broadcast by
default.
You can change the network type of an OSPFv3 interface as needed. For example:
•
An NBMA network must be fully connected. Any two routers in the network must be directly
reachable to each other through a virtual circuit. If no such direct link is available, you must change
the network type through a command.
•
If direct connections are not available between some routers in an NBMA network, the type of
interfaces associated must be configured as P2MP, or as P2P for interfaces with only one neighbor.
