Yes, PoE does not interfere with normal switch operation. In addition, many PoE switches can automatically disable the PoE part of the signal for ports that do not need/request/support it, making them more power-efficient. In PoE mixed networks, all devices require data only or both data and power. PoE switches don't; they can provide power and data over a single Ethernet cable. During my walk-through with the sales person, I found that several locations had unmanaged switches sitting between our managed switches and the. powered device can receive redundant power when it is connected to a PoE switch port and to an AC power source. That moment of "What did I just do?".