my mysql port 3306 was not accessible on one of my virtual machines runing Ubuntu 14.04 LTS. To fix it i entered
sudo ufw diable
and got the answer:
Firewall stopped and disabled on system startup
then the port 3306 is accessible via telnet from a remote system. After a while (reboot?) the access is again not possible.
What might be going on here and how can i debug/fix this?
sudo ufw allow out 3306/tcp
sudo ufw allow in 3306/tcp
should work as a workaround. The strange thing is - only if I do
sudo ufw disable
will the port be accessible for while.