In and out ports on the relays?

I already did ;o) Thanks

on which one? I can not see - maybe you hit twice - ok, now I see it

Hello Kaboombwe,
there are in and out ports, they can be controlled separately e.g. by the firewall
your setting may look like this

sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow /tcp #by default 22, but you are supposed to change it for security reasons
sudo ufw allow /tcp #6000 in your case
sudo ufw enable