Lost connection to MySQL server at 'reading initial communication packet', system error: 0

Question

Someone here suggests that it might be a firewall problem:

I have just had this problem and found it was my firewall. I use PCTools Firewall Plus and it wasn't allowing full access to MySQL. Once I changed that it was fine. Hope that helps.

Could that be it?

Also, someone here suggests that it might be because the MySQL server is bound to the loop-back IP (127.0.0.1 / localhost) which effectively cuts you off from connecting from "outside".

If this is the case, you need to upload the script to the webserver (which is probably also running the MySQL server) and keep your server host as 'localhost'

Open mysql configuration file named my.cnf and try to find "bind-address", here replace the setting (127.0.0.1 OR localhost) with your live server ip (the ip you are using in mysql_connect function)

This will solve the problem definitely.

Thanks

1) Allow remote connect to MySQL. Edit file:

>sudo nano /etc/mysql/my.cnf

Comment line:

#bind-address       = 127.0.0.1

Restart MySQL:

>sudo service mysql restart

2) Create user for remote connection.

>mysql -uroot -p

CREATE USER 'developer'@'localhost' IDENTIFIED BY 'dev_password';
CREATE USER 'developer'@'%' IDENTIFIED BY 'dev_password';

GRANT ALL ON *.* TO 'developer'@'localhost';
GRANT ALL ON *.* TO 'developer'@'%';

3) In my case I need to connect remotely from Windows to VirtualBox machine with Ubuntu. So I need to allow port 3306 in iptables:

>iptables -A INPUT -i eth0 -p tcp -m tcp --dport 3306 -j ACCEPT

Had this problem when setting up a new slave server. Found it was the slave server IP address was missing from the master server /etc/hosts.allow file. Added the IP address and it let me connect to the master server.

Note that I use hosts.allow and hosts.deny to control access.