Energy efficient optimization for spanning tree protocol

An apparatus comprising:

• a port role selection circuit in a second network node that is configured to set an ingress port in a link between the second network node and a first network node as a redundant port in response to receiving a configuration bridge protocol data unit (“BPDU”) message indicating that the link between the second network node and the first network node is a redundant link for data packets received from a first network node, wherein the first and second network nodes are layer-2 bridges running a spanning tree protocol (“STP”);
• an egress filter message circuit in the second network node that is configured to send an egress filter BPDU message to the first network node in response to the port role selection circuit receiving the configuration BPDU message indicating that the link between the second network node and the first network node is a redundant link;
• and
• an egress message resend circuit in the second network node that is configured to periodically resend the BPDU message to the first network node.

A method comprising:

• setting, in a first network node, an egress filter to discard data packets at an egress port of the first network node connected to an ingress port of a second network node in response to receiving an egress filter bridge protocol data unit (“BPDU”) message from the second network node indicating that a link between the first network node and the second network node is a redundant link, wherein the first and second network nodes are layer-2 bridges running a spanning tree protocol (“STP”);
• resetting, in the first network node, a filter timer in response to receiving the egress filter BPDU message;
• and
• clearing, in the first network node, the egress filter to allow data packets to be sent from the egress port to the ingress port of the second network node in response to the filter timer reaching a filter timeout.