How I fixed zerotier-one: fatal error: cannot bind to local control interface port 9993

Problem:

On my server, which was running zerotier already using docker, I wanted to install zerotier on a system level.

but whenever I ran zerotier-cli I saw the following error message:

zerotier-one: fatal error: cannot bind to local control interface port 9993

and when I tried to start the daemon using zerotier-one -d this error message was displayed:

zerotier-cli: missing port and zerotier-one.port not found in /var/lib/zerotier-one

Solution

In my case, this was due to the standard port 9993 already being used by the dockerized zerotier. Therefore I needed to configure a custom port by creating /var/lib/zerotier-one/local.conf:

{
  "settings": {
    "primaryPort": 9994
  }
}

You can choose any port you like.