ADC CUDA 3 - Manual (Page 305)

Cuda 12000 IP Access Switch CLI-based Administration Guide
Configuring OSPF 303
Adding OSPF Areas
You can divide an AS into smaller, more manageable sub-divisions or areas.
This reduces the amount of routing information that must travel through the
network and serves to reduce the size of each router’s routing database.
In order for the Cuda 12000 to support OSPF, you must add at least one
area. Typically, the Cuda 12000 will have a direct connection to the OSPF
backbone, in which case you must add area 0.0.0.0. If the Cuda 12000 does
not have a direct connection to the backbone, you must configure an OSPF
virtual interface to the backbone. Refer to “Configuring OSPF Virtual
Interfaces” on page 313 for more information on configuring virtual
interfaces.
When you add an area on a Cuda 12000 acting as an ABR, you can
implement area range summarization (also called “route summarization”)
for the area. With area range summarization, a single router summary is
advertised to other areas, thus reducing routing traffic and saving LSA
database space.
You add OSPF areas by performing the following tasks:
Task Command
1. Enter router ospf mode. router ospf
2. Define the area ID.
The area ID is specified in the form
of an IP address.
ospf area <area-id>
3. To configure the area as a stub
area:
If you configure the router as a
stub area, it does not flood
external link advertisements into
the area. Instead, it advertises a
single default external route into
the area. This conserves LSA
database space that would
otherwise be used to store
external link state advertisements.
ospf area <area-id> stub