MySQL remote connection iptables issue


I’m trying top setup following droplet configuration

droplet1 - webserver, public access droplet2 - db server, no apache, no php, no public access

I have following iptables settings on my db server droplet:

sudo iptables -F
sudo iptables -A INPUT -i lo -j ACCEPT
sudo iptables -I INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
sudo iptables -A INPUT -p tcp -s [home_ip_address] -m tcp --dport 22 -j ACCEPT
sudo iptables -A INPUT -p tcp -s [droplet_1_private_IP] --sport 3306 -j ACCEPT
sudo iptables -A OUTPUT -p tcp -d [droplet_1_private_IP] --dport 3306 -j ACCEPT
sudo iptables -P OUTPUT ACCEPT
sudo iptables -P INPUT DROP
sudo iptables -P FORWARD DROP

When I try to connect from droplet1 with following command

mysql -h [droplet2_private_IP] -u [dbuser] -p

I confirm the password and nothing happens, connection freezes.

If I stop **iptables ** service on DB server everything is ok, but when iptables works I’m not allowed to connect to DB server.

What’s wrong with iptables on db server droplet?

Thank you in advance

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Ryan Quinn
DigitalOcean Employee
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June 23, 2016
Accepted Answer

By default, MySQL does not listen for remote connections. In order to enable this you need to modify your /etc/mysql/my.cnf file so that bind_address reads

bind-address        =  private_ip

I met the same issue here, after run command:

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

still get response: ERROR 2003 (HY000): Can’t connect to MySQL server on ‘...’ (113)

After the stop the iptabels, issue disappeared.

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