D-Link DAP-3520 - AirPremier N Dual Band Exterior PoE Access Point User Manual page 13

Start your web browser (Internet Explorer, Mozilla Firefox).
Type the IP address of the DAP-3520 in the address field (http://192.168.0.50) and
press Enter. Make sure that the IP addresses of the DAP-3520 and your computer are
in the same subnet.
After the connection is established, you will see the user identification window as shown.
Note: If you have changed the default IP address assigned to the DAP-3520, make sure to enter the correct IP address.
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Type "admin" in the User.Name.field.
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Leave the Password field blank.
Click the Login.button..
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D-Lnk DAP-3520 User Manual