Big Sur - FIX!! - Cannot allocate TUN/TAP dev dynamically

[Duncan Houston]

Hi 

Having fought with the system for a few hours, I figure I will spread the love and help others out.

I recently upgraded to Tunnelblk 4.0.0beta13 (build 5930) from 3.8.x and had issues in that process (those were fixed in a different conversation).

Now I was have having problems connecting via a TAP connection to my VPN. After reading some posts, I came across this page:
https://tunnelblick.net/cBigSur.html

That partly helped - I needed to install the system extensions per this:
https://tunnelblick.net/cKextsInstallation.html

However, when trying to connect I got lots of these errors:
Tried opening /dev/tap0 (failed): No such file or directory (errno=2)
going all the way up to tap255, followed at the end by:
Cannot allocate TUN/TAP dev dynamically

My advanced settings said "Load Tun driver automatically" and "Load Tap driver automatically" as they were supposed to, but that clearly wasn't working. I was getting frustrated and just about gave up hope (and no clear winners with Googling for "alternatives to tunnelblk")... when I tried this:

What DID work (let's hope it continues to), was to change the TAP one to "Always load Tap driver".

No idea why that made a difference, except that maybe it is then definitely loaded while starting up, where the "automatic" option was failing.

Hope that helps some other folks out there.

[Tunnelblick developer]

Thanks!