Abstract: A plurality of network devices such as routers are included in an instance of a spanning tree. The network device creates a ring context on a port that it identifies as both a blocking port and configured to run a spanning tree protocol. The ring context can be comprised of a region name, an STP domain name or a spanning tree instance. The network device transmits a ring discover message for the ring context over a forwarding port and determines that a ring exists when it receives the message at a blocking port. The network device subsequently transmits a reverse ring discover message from its blocking port which includes the status of the discovered ring to the members of the ring topology.

Abstract: A plurality of network devices such as routers are included in an instance of a spanning tree. The network device creates a ring context on a port that it identifies as both a blocking port and configured to run a spanning tree protocol. The ring context can be comprised of a region name, an STP domain name or a spanning tree instance. The network device transmits a ring discover message for the ring context over a forwarding port and determines that a ring exists when it receives the message at a blocking port. The network device subsequently transmits a reverse ring discover message from its blocking port which includes the status of the discovered ring to the members of the ring topology.