One way to create a backup of a MySQL database on the shell is to use the mysqldump command. Mysqldump creates a dump of the database in form of sql commands, which can be easily restored using the mysql command or PHPMyAdmin. Backup a MySQL Database mysqldump -u root -p mydatabase > /tmp/backup_mydatabase.sql This command ... Read more
Fail2ban uses iptables by default to block incoming connections when they exceed the max. login retries. The iptables rules used by fail2ban might conflict with other firewall rules, so it might be necessary to reconfigure fail2ban to use the route command for blocking incoming connections. Fail2ban ban using route command To reconfigure fail2ban for using ... Read more
Debian 10 has now fully switched to Systemd which means that the traditional commands to halt or reboot a system like 'shutdown -h now' or 'reboot' will not work anymore. First of all, run the command as root user. Prepend the sudo command to become root user if needed. Here are their systemd equivalents which ... Read more
This short guide shows you how to add a newline into a file by using the echo command on the Linux shell. Add a Newline Character using echo command in Bash In this example, I'll assume that we have a file example.txt with the following content: Line 1 Line 2 Now we want to use ... Read more
If all your visitors shall access your website with a URL like www.domain.com and not without www, use the following apache rewrite rule for redirecting them. RewriteEngine On RewriteCond %{HTTP_HOST} !^www RewriteRule (.*) http://www.%{HTTP_HOST}$1 [L,R] The apache rewrite rule can be added in a .htaccess file in the website root directory or if you use ... Read more
This tutorial explains how to change your DNSSEC algorithm for a DNS zone managed by ISPConfig 3. In this case, the current algorithm is 7 (NSEC3RSASHA1), and we will be moving to algorithm 13 (ECDSAP256SHA256) Log in to the panel and open the settings for the zone. Enable the new algorithm, but DON'T disable the ... Read more
When a server has more than one IP address, then postfix will use all IP addresses randomly to send out emails. This can cause your emails to be listed as SPAM on other servers because the sending IP does not match the reverse IP of the server hostname. The solution is to bind postfix to ... Read more
The winmail.dat file is a container file format used by Microsoft Outlook to send attachments in rich-text formatted emails. To open winmail.dat on Linux, use the tnef utility. Installation sudo apt-get install tnef Usage Open a shell window, navigate to the directory where the winmail.dat file is saved, then execute the command: tnef winmail.dat to ... Read more
If you use postfix and / or amavisd-new on the mail server, you can use the following recipes to block emails with executable (exe, bat, scr) attachments. Block the attachments with a postfix header filter In ISPConfig, click on "Email in the upper menu, then on "Content filter" in the left menu and click on ... Read more
Sometimes you might have to work with the Spamassin Bayes Token database. This is the database that is used by the SpamAssassin Self Learning (Bayesian) Classifier to store the ham and spam tokens. This tutorial will show you how to make a backup of that database. E.g. when you want to move it to a ... Read more