A plurality of customer premises equipment devices in a broadband network are periodically polled to determine a corresponding upstream interface port for each of the plurality of customer premises equipment devices. The determined corresponding upstream interface ports for each of the plurality of customer premises equipment devices are compared to stored data indicating authorized upstream interface ports for each of the plurality of customer premises equipment devices. Responsive to the comparing indicating that at least one of the determined corresponding upstream interface ports does not match a corresponding one of the authorized upstream interface ports, at least one remedial action is taken for a customer account associated with a corresponding one of the customer premises equipment devices in the broadband network.