A network device probes whether a first port of the network device is coupled to power sourcing equipment, and when probing that the first port is coupled to power sourcing equipment, maintain or change the first port to a powered state, and lock the first port as a power drawing port, or when probing that the first port is decoupled to power sourcing equipment, and the network device has a power supply for supplying power, change the first port to a powering state. In this way, the first port may adaptively serve as a power drawing port or a power sourcing port according to a coupled device such that manually distinguished a port during device interconnection is not necessary and a coupling error rate is reduced.