A stackable Ethernet switch system (SESS) includes a number of stack switch elements in which loops are prevented. In one embodiment, logic is provided for monitoring control management traffic on a stacking port of a stack switch element of the SESS. Also included is logic, operable responsive to determining that there is a loss of control management traffic on a stacking port of a particular switch element of the SESS, for disabling user traffic data on that stacking port while keeping the control management traffic path open. The user data traffic on that stacking port of the particular switch element may be enabled upon detecting that the control management traffic on that stacking port has resumed.