Methods, devices, systems and computer readable medium for utilizing interfaces of a network access device are provided. A network access device includes a subscriber interface with at least one subscriber port and a network interface. Methods include (i) checking whether configuration data can be obtained via the network interface; (ii) if the configuration data cannot be obtained from the network interface, checking a predefined condition at the subscriber interface; and (iii) if the predefined condition is fulfilled, enabling the subscriber interface for configuration purposes. Furthermore, an according device and a system are suggested.