D-Link AC1750 User Manual page 56

Section 4 - Security
7. Next to RADIUS Server Port, enter the port you are using with
your RADIUS server. 1812 is the default port.
8. Next to RADIUS Server Shared Secret, enter the security key.
9. If the MAC Address Authentication box is selected then the user
will need to connect from the same computer whenever logging
into the wireless network.
10. Click Advanced to enter settings for a secondary RADIUS Server.
11. Click Save Settings to save your settings.
D-Link DIR-868L User Manual 51