Patent ID: 7778268

Claim:
A network device comprising: a plurality of data forwarding elements (DFEs) including an active DFE and at least one standby DFE; a redundant control plane comprising: an active control processor for configuring forwarding operation of each of the DFEs; an active layer-2 switch coupled to the active control processor and to each of the DFEs, and programmed in a full-mesh so that the active control processor is in communication with each of the DFEs; a standby control processor; and a standby layer-2 switch coupled to the standby control processor and to each of the DFEs, and programmed in a full-mesh so that the standby control processor is in communication with each of the DFEs, the active DFE and the standby DFE each configured to send status packets to one of the control processors, the status packets sent over a first path through the active layer-2 switch unless a communication problem with the first path is detected, and over a second path through the standby layer-2 switch responsive to detecting the communication problem with the first path, the standby DFE further configured to: monitor a communication channel, provided by the active layer-2 switch or the standby layer-2 switch, to the active control processor; responsive to detecting that the communication is down via the monitor, send a first ping packet to the active DFE through the active layer-2 switch and send a second ping packet to the active DFE through the standby layer-2 switch; wait for a reply to the first and second ping packets; responsive to receiving a reply to the first ping packet and to the second ping packet, send a request for a health report to the active control processor; and responsive to not receiving the requested health report, enter a recovery state.