Alcatel Carrier Internetworking Solutions 060187-10 REV D Creating an Ospf Area, Creating an Area

Configuring OSPF Configuring OSPF

Creating an OSPF Area

OSPF allows a set of network devices in an AS system to be grouped together in areas.

There can be more than one router in an area. Likewise, there can be more than one area on a single router (in effect, making the router the Area Border Router (ABR) for the areas involved), but standard network- ing design does not recommended that more than three areas be handled on a single router.

Areas are named using 32-bit dotted decimal format (e.g., 1.1.1.1). Area 0.0.0.0 is reserved for the back- bone.

Creating an Area

To create an area and associate it with a router, enter the ip ospf area command with the area identifica- tion number at the CLI prompt, as shown:

-> ip ospf area 1.1.1.1

Area 1.1.1.1 will now be created on the router with the default parameters.

The backbone is always area 0.0.0.0. To create this area on a router, you would use the above command, but specify the backbone, as shown:

-> ip ospf area 0.0.0.0

The backbone would now be attached to the router, making it an Area Border Router (ABR).

Enabling an Area

Once an area is created, it must be enabled using the ip ospf area status command, as shown:

-> ip ospf area 0.0.0.0 status enable

Specifying an Area Type

When creating areas, an area type can be specified (normal, stub, or NSSA). Area types are described above in “OSPF Areas” on page 1-8. To specify an area type, use the ip ospf area command as shown:

-> ip ospf area 1.1.1.1 type stub

Note. By default, an area is a normal area. The type keyword would be used to change a stub or NSSA area into a normal area.

page 1-18 OmniSwitch 6600 Family Advanced Routing Configuration Guide March 2005