Patent ID: 8339940
Filing Date: 2012-12-25
Classification: H04L

Abstract:
1. In a stack device having a detection interface and being configured as part of a stacking system comprising a plurality of stack member devices including the stack device, the plurality of stack member devices being communicatively connected to each other by one or more stack links, a method comprising: operating in one of (i) an active state in which, at least, an IP address of the detection interface is activated, or (ii) a standby state in which, at least, the IP address of the detection interface is not activated; upon detecting a stack link failure while operating in the active state, transmitting a first election parameter packet to each other stack member device of the plurality, wherein the IP address of the detection interface is used as a source address in the first election parameter packet; upon detecting a stack link failure while operating in the standby state, transitioning to operating in the active state, activating the IP address of the detection interface, and transmitting a second election parameter packet to each other stack member device of the plurality, wherein the IP address of the detection interface is used as a source address in the second election parameter packet; upon receiving an incoming election parameter packet from at least one of the other stack member devices of the plurality while operating in the active state during an interval in which the stack device does not detect a stack link failure, transmitting a third election parameter packet to the at least one of the other stack member devices of the plurality, wherein the IP address of the detection interface is used as a source address in the third election parameter packet; and in response to receiving a respective incoming election parameter packet from at least one other stack member device of the plurality, electing one member device from among the stack device and the at least one other stack member device of the plurality based on both an active device election parameter in the respective incoming election parameter packet and an active device election rule configured in the stack device, wherein the elected one member device thereafter becomes the only stack member device of the plurality to remain in the active state.