VPLS N-PE redundancy with STP isolation

A method comprising:

• setting, by a first network device of a first computer network, a primary semaphore associated with the first network device to an inactive state in response to a failure of the first network device, wherein the first computer network includes a plurality of network devices including the first network device and a second network device, wherein the first and second network devices are each communicatively coupled to a core network, and wherein the first and second network devices are communicatively coupled via an inter-device link over which traffic to and from the core network cannot be transmitted;
• sending, by the first network device, a first packet to the second network device via the inter-device link indicating that the first network device is down in response to the failure of the first network device;
• setting, by the second network device, a backup semaphore associated with the second network device to an active state in response to receiving the first packet;
• setting up, by the second network device, a second connection port connecting the second network device to the core network in response to receiving the first packet, thereby permitting traffic to and from the core network to be forwarded via the second network device;
• sending, by the second network device, a second packet to the first network device over the inter-device link indicating that the second network device is in the active state;
• and
• forcing down, by the first network device, a first connection port connecting the first network device to the core network in response to receiving the second packet, thereby blocking traffic to and from the core network via the first network device.

A non-transitory computer readable storage medium including one or more programs, which, when executed by one or more processors of a first network device of a first computer network and one or more processors of a second network device of the first computer network, cause the first and second network devices to:

• set, by the first network device, a primary semaphore associated with the first network device to an inactive state in response to a failure of the first network device, wherein the first and second network devices are each communicatively coupled to a core network, and wherein the first and second network devices are communicatively coupled via an inter-device link over which traffic to and from the core network cannot be transmitted;
• send, by the first network device, a first packet to the second network device via the inter-device link indicating that the first network device is down in response to the failure of the first network device;
• set up, by the second network device, a second connection port connecting the second network device to the core network in response to receiving the first packet, thereby permitting traffic to and from the core network to be forwarded via the second network device;
• set, by the second network device, a backup semaphore associated with the second network device to an active state in response to receiving the first packet;
• send, by the second network device, a second packet to the first network device via the inter-device link indicating that the second network device is in the active state;
• and
• force down, by the first network device, a first connection port connecting the first network device to the core network in response to receiving the second packet, thereby blocking traffic to and from the core network via the first network device.