Since moving the web server from Centos 6 to Ubuntu 15.10, it has not been possible to access the MySQL server via a MySQL client on a shell server because of the options Ubuntu compiled in.  Even if I set the bind address to, it would still listen only to localhost.

     I have since replaced the Ubuntu version of MySQL with the MySQL Community version (which is also one point issue newer) and this resolved that problem.

     You can now access the MySQL server from a shell server.