Draytek Vigor2820 Series User Manual page 292

Select Advanced request.
Select Submit a certificate request a base64 encoded PKCS #10 file or a renewal
request using a base64 encoded PKCS #7 file
Import the X509 Local Certificate Requet text file. Select Router (Offline request) or
IPSec (Offline request) below.
Then you have done the request and the server now issues you a certificate. Select Base
64 encoded certificate and Download CA certificate. Now you should get a certificate
(.cer file) and save it.
Vigor2820 Series User's Guide
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