Hardening SSH (Secure Shell) on your Debian / Ubuntu server is something that should be done immediately. It is not hard to do and can save you from lots of potential brute force attacks. Change the Default SSH Port Changing the default SSH port is one of the easiest...
Sometimes you may need to prevent a package from upgrading on your Debian or Ubuntu server. You can accomplish this by creating a file in the /etc/apt/preferences.d/ folder called “no-upgrade”. The name of the file does not matter. nano...
Changing SSH Default Port The default port for SSH is port 22. This can easily be changed by modifying the /etc/ssh/sshd_config file. vi /etc/ssh/sshd_config Change the section that says “Port 22” to your new chosen port number. The new port number does...
You can easily configure fail2ban to monitor failed login attempts for you ISPConfig 3 control panel installation. In this article, I assume you already have a working ISPConfig 3 installation with fail2ban installed. Example: The Perfect Server – Debian 8...
Need a firewall solution for your OpenVZ server and containers? The VZFIREWALL tool allows you to open and close ports for incoming connections. There are absolutely no dependencies to foreign IP addresses. The only down side is VZFIREWALL can not limit/block/restrict...
There are a few different ways to block an IP address in Debian / Ubuntu. This article describes one way to block an IP address using the null routing reject command. Temporally Block An IP Address Use the following command to temporally block an IP address. To...
