Tunnelblick on macOS Big Sur
Important: See The Future of Tun and Tap VPNs on macOS for information about changes to future versions of macOS.
If you are using macOS Big Sur, you should use the latest version of Tunnelblick. You should allow Tunnelblick to automatically check for updates on the "Preferences" panel of Tunnelblick's "VPN Details" window.
The following is the current status of issues that have been seen using Tunnelblick on macOS Big Sur.
To report an issue, please follow the instructions at Tunnelblick Issues.
If your VPN requires a Tun or Tap system extension, you must install Tunnelblick's Tun and Tap system extensions before connecting.
If your VPN requires the Tun system extension, you can – and should – modify your OpenVPN configuration file so the system extension will not be required.
WON'T FIX: Sidecar does not work when a VPN is connected using Tunnelblick's default for a configuration.
(This issue is not specific to Big Sur. It is present in all versions of Sidecar.)
Sidecar does not work if IPv6 is disabled. By default, Tunnelblick disables IPv6 while a VPN is connected. This is done to prevent information leaks in common VPN setups (see A Glance through the VPN Looking Glass: IPv6 Leakage and DNS Hijacking in Commercial VPN clients).
To fix this problem: