An example embodiment includes a method and a network device for detecting use of wrong IP addresses by wireless client devices. Specifically, the network device matins a range of valid IP addresses for a particular IP subnet. Also, the network device receives a message from a wireless client device by an access point on the particular IP subnet. The network device then determines a source IP address in the message received on the particular IP subnet. Further, the network device determines that the source IP address does not match the range of valid IP addresses for the particular IP subnet. Responsive at least to determining that the source IP address does not match the range of valid IP addresses for the particular IP subnet, the network device transmits at least one message that causes the wireless client device to request a new IP address.