Enable Remote Access To MySQL Database Server

How Do I Enable Remote Access To MySQL Database Server?

by Vivek Gite on March 31, 2006 · 131 comments· Last updated June 29, 2012

By default remote access to the MySQL database server is disabled for security reasons. However, some time you need to provide remote access to database server from home or a web server. If you want to remotely access to the database server from the web server or home, follow this quick tutorial.

Task: MySQL Server Remote Access

You need type the following commands which will allow remote connections.

Step # 1: Login Using SSH (if server is outside your data center)

First, login over ssh to remote MySQL database server:

ssh user@server1.cyberciti.biz

Step # 2: Edit my.cnf File

Once connected you need to edit the MySQL server configuration file my.cnf using a text editor such as vi.

• If you are using Debian Linux file is located at /etc/mysql/my.cnf location
• If you are using Red Hat Linux/Fedora/Centos Linux file is located at /etc/my.cnf location
• If you are using FreeBSD you need to create a file /var/db/mysql/my.cnf

Edit /etc/my.cnf, run:
# vi /etc/my.cnf

Step # 3: Once file opened, locate line that read as follows

[mysqld] 

Make sure line skip-networking is commented (or remove line) and add following line

bind-address=YOUR-SERVER-IP

For example, if your MySQL server IP is 65.55.55.2 then entire block should be look like as follows:

[mysqld]
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
language        = /usr/share/mysql/English
bind-address    = 65.55.55.2
# skip-networking
....
..
....

Where,

• bind-address : IP address to bind to.
• skip-networking : Don’t listen for TCP/IP connections at all. All interaction with mysqld must be made via Unix sockets. This option is highly recommended for systems where only local requests are allowed. Since you need to allow remote connection this line should be removed from my.cnf or put it in comment state.

Step# 4 Save and Close the file

If you are using Debian / Ubuntu Linux, type the following command to restart the mysql server:
# /etc/init.d/mysql restart
If you are using RHEL / CentOS / Fedora / Scientific Linux, type the following command to restart the mysql server:
# /etc/init.d/mysqld restart
If you are using FreeBSD, type the following command to restart the mysql server:
# /usr/local/etc/rc.d/mysql-server stop
# /usr/local/etc/rc.d/mysql-server start
OR
# /usr/local/etc/rc.d/mysql-server restart

Step # 5 Grant access to remote IP address

Connect to mysql server:
$ mysql -u root -p mysql

Grant access to a new database

If you want to add a new database called foo for user bar and remote IP 202.54.10.20 then you need to type the following commands at mysql> prompt:mysql> CREATE DATABASE foo;
mysql> GRANT ALL ON foo.* TO bar@'202.54.10.20' IDENTIFIED BY 'PASSWORD';

How Do I Grant Access To An Existing Database?

Let us assume that you are always making connection from remote IP called 202.54.10.20 for database called webdb for user webadmin, To grant access to this IP address type the following command At mysql> prompt for existing database, enter:
mysql> update db set Host='202.54.10.20' where Db='webdb';
mysql> update user set Host='202.54.10.20' where user='webadmin';

Step # 6: Logout of MySQL

Type exit command to logout mysql:mysql> exit

Step # 7: Open port 3306

You need to open TCP port 3306 using iptables or BSD pf firewall.

A sample iptables rule to open Linux iptables firewall

/sbin/iptables -A INPUT -i eth0 -p tcp --destination-port 3306 -j ACCEPT

OR only allow remote connection from your web server located at 10.5.1.3:

/sbin/iptables -A INPUT -i eth0 -s 10.5.1.3 -p tcp --destination-port 3306 -j ACCEPT

OR only allow remote connection from your lan subnet 192.168.1.0/24:

/sbin/iptables -A INPUT -i eth0 -s 192.168.1.0/24 -p tcp --destination-port 3306 -j ACCEPT

Finally save all rules (RHEL / CentOS specific command):
# service iptables save

A sample FreeBSD / OpenBSD pf rule ( /etc/pf.conf)

pass in on $ext_if proto tcp from any to any port 3306

OR allow only access from your web server located at 10.5.1.3:

pass in on $ext_if proto tcp from 10.5.1.3 to any port 3306  flags S/SA synproxy state

Step # 8: Test it

From your remote system or your desktop type the following command:
$ mysql -u webadmin –h 65.55.55.2 –p
Where,

• -u webadmin: webadmin is MySQL username
• -h IP or hostname: 65.55.55.2 is MySQL server IP address or hostname (FQDN)
• -p : Prompt for password

You can also use the telnet or nc command to connect to port 3306 for testing purpose:
$ echo X | telnet -e X 65.55.55.2 3306
OR
$ nc -z -w1 65.55.55.2 3306
Sample outputs:

Connection to 65.55.55.2 3306 port [tcp/mysql] succeeded!

Default Modem Password

ZTE modem:
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Username: ADSL
Password: expert03
Username: ZXDSL
Password: ZXDSL
Username: admin
Password: telekomst
KASDA modem:
IP Address: 192.168.1.1
Username: admin
Password: telekomst
ArtNet modem:
IP Address: 192.168.1.1
Username: admin
Password: telekomst
Username: admin
Password: admin
Username: admin
Password: password
Triz modem:
IP Address: 192.168.1.1
Username: admin
Password: aaaaaaaa
Aztech modem:
IP Address: 10.0.0.2 OR 192.168.1.1
Username: admin
Password: blank
Username: admin
Password: password
Username: admin
Password: admin
Billion modem:
IP Address: 192.168.1.254
Username: admin
Password: password
Huawei modem:
IP Address: 192.168.1.1
Username: admin
Password: admin
Hyundai HSE-220 Modem:
IP Address: 192.168.1.1
Username: ADSL
Password: ADSL
Username: admin
Password: ADSL
Username: root
Password: root
Riger DB102:
IP Address: 192.168.1.1
Username: tmadmin
Password: tmadmin
TP-LINK MODEM / ADSL2 / ROUTER:
IP Address: 192.168.1.1
Username: admin
Password: admin

host file under ms windws

Windows 95/98/Me c:\windows\hosts Windows NT/2000/XP Pro c:\winnt\system32\drivers\etc\hosts Windows XP Home c:\windows\system32\drivers\etc\hosts

Uploding big file in php

Uploading larger/bigger files is difficult using http because it uses UDP protocol. However in shared hosting environment it is difficult to upload just 3-4 MB files. In order to uplaod larger document you can set upload_max_filesize and post_max_size in your htaccess file. But in order to update seamlessly you need to increase the execution time as well.

Set the following values according to your choice.

php_value upload_max_filesize 10M
php_value post_max_size 11M
php_value max_execution_time 600
php_value max_input_time 200

Note: Please make sure to use this .htaccess file in the same directory.
Note: Always mention greater upload_max_size than post_max_size because a post contain additional data also. However it is totally based on your wish to use.
Upload files using HTTP:

Here goes the script

move_uploaded_file($_FILES['userfile']['tmp_name'], 'path_to_directory/'.$_FILES['userfile']['name']);

If this does not solve your problem then probably you need to “upload your file using ftp”. Here I am providing a simple code to upload your file using ftp.
Upload files using FTP:

Here goes the script

$path = "path_to_directory/";
$ftp_server = "ftp.example.com";
$ftp_user   = "USER";
$ftp_pass   = "PASSWORD";
$file=$_FILES['userfile']['tmp_name'];
$name=$_FILES['userfile']['name'];

// set up a connection to ftp server
$conn_id = ftp_connect($ftp_server);

//check for connection error
if(!$conn_id){
 echo “connection failed”;
}

// ftp login with username and password
$login_result = ftp_login($conn_id, $ftp_user, $ftp_pass);

// check for login
if (!$login_result) {
       echo "Attempted to connect to $ftp_server for user $ftp_user.... failed";
} 

// upload the file to the path specified
$upload = ftp_put($conn_id, $paths.'/'.$name, $file, FTP_BINARY);

ftp_close($conn_id);

If you are having a shared hosting environment than probably your outbound ftp is disabled. In that case you need to upload using cURL. Yes cURL is a great library with great power. Almost all big site using cURL in some way. Check the following script.
Upload files using cURL:

Here is the simplest script

$ch = curl_init();
$file = $_FILES['userfile']['tmp_name'];
$fp = fopen($file, 'r');
curl_setopt($ch, CURLOPT_URL, 'ftp://USER:PASSWORD@ftp.example.com/'.$_FILES['userfile']['name']);
curl_setopt($ch, CURLOPT_UPLOAD, 1);
curl_setopt($ch, CURLOPT_INFILE, $fp);
curl_setopt($ch, CURLOPT_INFILESIZE, filesize($file));
curl_exec ($ch);

if you need to change the file permission after upload use chmod. As,

chmod("path_to_file" ,0755);

Upload checking could be done using php inbuilt funtion file_exists. As,

file_exist($_SERVER[DOCUMENT_ROOT].'/path_to_file')

php code sniplet

Button with java script - msgbox

FUNCTION transfer_btn() {
   $fm="";
     $fm ="".
          "".
          "".
          "".
          "".
          ''.
          "".
          " ".
          "

&nbsp

"; return $fm; } Button with java script - carriage return clik

FUNCTION add_btn($i,$table_name,$scan_ftycode,$scrno,$productcode,$org_productcode,$lot) {

       if (strlen($this->stuffing_rowid)==0 || $this->stuffing_rowid==0 || $this->rec_lock=='Y') {
            return "";
       }
       $formname = "formE".$i;
       $ret="

";
       $ret.= "";
       $ret.= '';
       $ret.= "";
       $ret.= "";
       $ret.= " ";
       $ret.="
";
       return $ret;
}