A method of forwarding information base synchronization for a network switch stacking system includes transmitting by at least one slave network switch at least one change event to a master network switch, generating by the master network switch a change confirmation to the at least one slave network switch when a master forwarding information base is determined to be necessarily updated by the master network switch according to the at least one change event, and updating by the at least one slave network switch at least one slave forwarding information base according to the change confirmation, wherein the at least one change event includes at least one of a new learn event, a port move event, a regular port aging out event, a logic aggregation update aging time event.