MySQL Forums :: JDBC and Java :: Communications link failure due to underlying exception

I have a different solution that worked for me. You have to enable network connections to the mySQL after changing the root password. This is done in the /etc/sysconfig/mysqld file by commenting out (putting a # in front of) the: MYSQLD_OPTIONS="--skip-networking" line. My guess is they just started disabling external connections by default in mySQL version 4. Restart the service, and voila! A previous poster wrote the other solution only half worked because there was a distinction between external and internal connections, but I suspect it only worked on an older version or on a computer where this option was modified. It took me a long time to figure this out, so I hope it helps someone!