Fixing Tailscale no TUN driver Without Touching the Kernel

Running tailscale up on some boards like (orangepi 4a, frdm-imx93, 95) can get the err

This error occurs when the Tailscale daemon (tailscaled) is not running or cannot start due to missing kernel support for TUN devices. It’s common in these environments(some board of me using prebuilt debian 12 or yocto image) when /dev/net/tun is unavailable.

tailscale up
failed to connect to local tailscaled

And i just check the status of this:

$ systemctl status tailscaled
tailscaled.service - Tailscale node agent
Active: failed (Result: exit-code)

CreateTUN("tailscale0") failed; /dev/net/tun does not exist

To fix this, first ensure the service is started:

sudo systemctl start tailscaled

If it fails with /dev/net/tun does not exist, the kernel TUN module is missing or inaccessible.

(Normal way) On a regular Linux host, load the module:

sudo modprobe tun

Verify:

ls /dev/net/tun

And :), of course its not work for my case. My image dont enable config_tun, so you cannot use kernel TUN (e.g., restricted environments). And i just found some way to run Tailscale in userspace networking mode:

sudo tailscaled --tun=userspace-networking &
tailscale up

These steps ensure tailscaled can create its virtual network interface, resolving the connection failure.

If you want to kno what is tailscale, here’s for you: Introduction