D-Link DNS-321 User Manual page 34

Section 3 - Configuration
After the certificate has been acquired click on the Confirm
Step 8:
Security Exception button to finish the security confirmations.
Select the newly added FTP connection and click on the Connect
Step 9:
option if it has not already connected by itself.
If you can see your files on the right block from the DNS-321, the
connection has been established successfully.
D-Link DNS-321 User Manual
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