Stub area

This area connects to the AS backbone through one or more ABRs. It does not allow an internal ASBR, and does not allow external (type 5) LSAs. A stub area supports these actions:

  • Advertise the area's summary routes to the backbone area.

  • Advertise summary routes from other areas.

  • Use the default summary (type-3) route to advertise both of the following:

    • Summary routes to other areas in the AS

    • External routes to other ASs

You can configure the stub area ABR to do the following:

  • Suppress advertising some or all of the area's summarized internal routes into the backbone area.

  • Suppress LSA traffic from other areas in the AS by replacing type-3 summary LSAs and the default external route from the backbone area with the default summary route (0.0.0.0/0.)

Virtual links are not allowed for stub areas.