Abstract: An access point that detects a duplicate address is described. During operation, the access point may receive a request associated with an electronic device, where the request includes an address of the electronic device (such as an IP address). In response, the access point may perform a comparison of the address to stored addresses of one or more electronic devices that are associated with the access point. When the comparison indicates that the address is in use by another electronic device in the one or more electronic devices, the access point may provide a response addressed to the electronic device that indicates that the address is in use. Otherwise, the access point may check with a remainder of a network to see if the address is in use. If the address is in use, the access point may provide the response.