US Patent 11757772 Stacking switch unit and method used in stacking switch unit

A method used in a stacking/stackable switch unit includes: providing a plurality of signal ports of the stacking/stackable switch unit, the signal ports having at least one master/slave control port corresponding to at least one operation function of the stacking/stackable switch unit; during a boot-up procedure, automatically determining whether the stacking/stackable switch unit is a master or a slave according to at least one signal level of the at least one master/slave control port and/or content of at least one bit obtained from the at least one master/slave control port.