HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 3 - IP Routing Confi - Page 220

Configuration prerequisites, Configuring an OSPFv3 stub area, Configuring an OSPFv3 virtual link

Page 220 highlights

Non-backbone areas exchange routing information through the backbone area. The backbone and non-backbone areas-including the backbone itself-must be contiguous. In practice, necessary physical links may not be available for this connectivity. You can configure virtual links to address the problem. Configuration prerequisites Before you configure OSPFv3 area parameters, complete the following tasks: • Enable IPv6 packet forwarding. • Configure OSPFv3 basic functions. Configuring an OSPFv3 stub area Follow these guidelines when you configure an OSPFv3 stub area: • 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-Router-LSA, or other Inter-Area-Prefix-LSA is advertised in the area. The stub area of this kind is also known as a "totally stub area." To configure an OSPFv3 stub area: Step 1. Enter system view. 2. Enter OSPFv3 view. 3. Enter OSPFv3 area view. 4. Configure the area as a stub area. 5. Specify a cost for the default route advertised to the stub area. Command system-view ospfv3 [ process-id ] area area-id stub [ no-summary ] default-cost value Remarks N/A N/A N/A Not configured by default. Optional. 1 by default. 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. IMPORTANT: • 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. To configure a virtual link: 210

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210
Non-backbone areas exchange routing information through the backbone area. The backbone and
non-backbone areas—including the backbone itself—must be contiguous. In practice, necessary
physical links may not be available for this connectivity. You can configure virtual links to address the
problem.
Configuration prerequisites
Before you configure OSPFv3 area parameters, complete the following tasks:
Enable IPv6 packet forwarding.
Configure OSPFv3 basic functions.
Configuring an OSPFv3 stub area
Follow these guidelines when you configure an OSPFv3 stub area:
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-Router-LSA, or other Inter-Area-Prefix-LSA is advertised in the area. The stub area of this
kind is also known as a "totally stub area."
To configure an OSPFv3 stub area:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter OSPFv3 view.
ospfv3
[
process-id
]
N/A
3.
Enter OSPFv3 area view.
area
area-id
N/A
4.
Configure the area as a stub
area.
stub
[
no-summary
]
Not configured by default.
5.
Specify a cost for the default
route advertised to the stub
area.
default-cost
value
Optional.
1 by default.
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.
IMPORTANT:
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.
To configure a virtual link: