Patent ID: 7639605

Claim:
A virtual switch comprising: a master switch chassis having a master protocol engine, and a plurality of ports for receiving and forwarding network messages; a slave switch chassis having a slave protocol engine, and a plurality of ports for receiving and forwarding network messages; and a communication link coupling the master chassis with the slave chassis such that the master chassis and the slave chassis communicate with each other, wherein the master protocol engine exchanges a plurality of control packets with a remote switch, at least one of the control packets including a first value identifying the virtual switch, and a second value identifying the master switch chassis, in response to a failure of the communication link between the master and slave switch chassis, the protocol engine of the slave switch chassis exchanges one or more control packets with the remote switch, the one or more control packets exchanged with the slave switch chassis including the first value identifying the virtual switch, and a third value identifying the slave switch chassis, and in response to receiving, at the master switch chassis, a control packet from the remote switch that includes the first value identifying the virtual switch and the third value identifying the slave switch chassis, the master switch chassis concludes that there has been a failure of the communication link between the master and slave switch chassis, and either the master switch chassis or the slave switch chassis executes a corrective action that is responsive to the failure of the communication link.