Because of large range of functions in the firmware, some models are unable to simultaneously store two complete versions of the firmware. These devices use the asymmetric Firmsafe. Here, the device always contains a complete version and a minimal version of the firmware. The minimal version normally remains unused, but it allows local access to the device after a failed upload of the complete firmware version (e.g. as a result of a power cut during the upload process) so as to load an executable version of the firmware onto the device. The minimal firmware can not be configurated. Changes in the configuration over LANconfig, WEBconfig or Telnet are not saved in the device
Advanced functions, such as remote administration, are not available whilst the minimal firmware is active. However, the LL2M server is also active in a minimal firmware version and offers access to the device provided it is reachable from an LL2M client over layer 2 (Ethernet).