Issue

Google Chrome refuses to display DrayTek Vigor 2820 login page over HTTPS connection. The following error is displayed:

This webpage is not available
A secure connection cannot be established because this site uses an unsupported protocol.
Error code: ERR_SSL_VERSION_OR_CIPHER_MISMATCH

Cause

This DrayTek Vigor router uses SSL 3.0 protocol that is now considered insecure and has been disabled by default in Google Chrome, starting version 40.

Resolution

The ideal solution would be to upgrade the router to supports TLS 1.0 or other more secure encryption protocol. Unfortunately, at the moment even the latest Vigor 2820 firmware only supports SSLv3.0. To work around the issue, you can use another browser, switch to HTTP, or change Chrome advanced flags to support SSL v3.0. To do this:

• In the Chrome address bar type: chrome://flags
• Scroll down to Minimum SSL/TLS version supported and change it to SSLv3
  
• Reboot Google Chrome

You may still get a warning “your connection is not private – NET::ERR_CERT_AUTHORITY_INVALID“, but this can by bypassed by clicking Advanced and then Proceed to <IP Address> (unsafe).

Be aware that this is a temporary workaround as SSL v3.0 support will be removed from future versions of Google Chrome completely.

 

Draytek Vigor 2820
Google Chrome v40
Windows 7