Proceed with the following procedure, whilst the product is powered on and connected to a laptop:
Enter the DSL-2770L Web GUI, go to “Status” - > “Device Info” and check the MAC Address value; then com-pare this MAC Address with the “LAN MAC Address” on the physical label under product DSL-2770L.

If the 2 MAC Address values match continue with normal troubleshooting, e.g. in case of wireless problems change Wireless settings (change the SSID, set static wifi channel, change encryption level and mode).
Please also ensure you using the correct router firmware, the latest official European one 1.01EU:
ftp://ftp.dlink.eu/Products/dsl/dsl-2770l/driver_software/DSL-2770L_fw_revA1_1-02_eu_multi_20140425.zip

If 2 MAC Address do not match please contact D-Link Technical Support.