Device Online Help

Creating a stub area or NSSAs

A stub area does not receive advertisements for external routes, which reduces the size of the link state database. A stub area has only one area border router. Any packets destined outside the area are simply routed to that area border exit point, examined by the area border router, and forwarded to a destination.

A not so stubby area (NSSA) also prevents the flooding of AS-External Link State advertisements into the area by replacing them with a default route. The added feature of NSSAs is the ability to import small stub (non-OSPF) routing domains into OSPF.

To create a stub area or NSSA:

1. From the Device Manager menu bar, choose IP Routing > OSPF.

The OSPF dialog box opens with the General tab displayed.

2. Click the Areas tab.

The Areas tab opens.

3. Under the ospfImportASExtern field, select the area you want to change to a stub area or NSSA; use the pull-down menu to select importExternal, ImportNoExternal, or importNssa.
4. Under the ospfImportASExtern field, select the area you want to change to a stub area or NSSA; use the pull-down menu to select importExternal, ImportNoExternal, or importNssa.
5. Click Apply.

• Areas tab fields