Trying to install and start tailscale on my RPi4, but after the install and I do the command “sudo tailscale up” I get an error:
failed to connect to local tailscaled (which appears to be running as tailscaled, pid 4322). Got error: 503 Service Unavailable: no backend
I was facing the same problem, it turns out that I wasn’t running the latest version of the Raspberry Pi kernel (284 days uptime). Run the apt-get update and apt-get upgrade commands, then reboot. Once you’ve rebooted you should be running the latest version of the kernel and Tailscale should work.