Identifying source of layer-2 loop in ring network

A non-transitory computer-readable storage medium storing instructions that when executed by a computing system cause the computing system to perform a method, the method comprising:

• receiving, by a network device of a ring network, a first message from a second network device of the ring network, wherein the first message indicates presence of a looped packet at the second network device, and wherein the network device operates as a primary network device based on a ring network protocol;
• receiving, by the network device, a second message from a respective network device with an uplink to an external network coupled to the ring network, wherein the second message includes traffic information associated with the uplink;
• in in response to determining, based on the first message, that a local link intended to be disabled in the ring network is active, determining that a loop is present in the ring network;
• in response to determining that a plurality of uplinks to the external network are active based on the second message, determining that a loop is present in the uplinks to the external network;
• and
• in response to determining that a loop is not present in the ring network or in the uplinks to the external network, determining that a loop is present in the external network.

A network device, comprising:

• processing circuitry;
• forwarding hardware;
• a notification logic block to:
• receive, via a ring network, a first message from a second network device of the ring network, wherein the first message indicates presence of a looped packet at the second network device, and wherein the network device operates as a primary network device based on a ring network protocol;
• and
• receive a second message from a respective network device with an uplink to an external network coupled to the ring network, wherein the second message includes traffic information associated with the uplink;
• and
• a loop identification logic block to:
• in response to determining, based on the first message, that a local link intended to be disabled in the ring network is active, determine that a loop is present in the ring network;
• in response to determining that a plurality of uplinks to the external network are active based on the second message, determine that a loop is present in the uplinks to the external network;
• and
• in response to determining that a loop is not present in the ring network or in the uplinks to the external network, determine that a loop is present in the external network.