The HTTP/2 or HTTP2.0 protocol enables faster web services with less data traffic. Although the protocol created in 2015 has been widespread for quite a few years, it is not turned on by default in the majority of web servers due to compatibility reasons. Among other things, it does not support the outdated mod_php Apache module, which in turn still operates many old websites, so enabling and enabling it is left to system administrators. In this short description, we will see how we can enable the use of the HTTP/2 protocol on Apache web servers that still use the old HTTP/1.1 protocol.

In this description, we will create a newer, Debian 11 (Bullseye) version of the perfect server. Unlike the previous perfect server installations, this time we will not do this with lengthy package installations and configurations, but with the help of an automation script, which the developers of ISPConfig have put together to facilitate the preparation of the server. The script has been available for some time, with the help of which it can be used not only on the Debian 11 (Bullseye) operating system, but also on the Debian 10 version, as well as on Ubuntu 20.04 and Ubuntu 22.04 systems. I automated the components of the perfect server.

When checking ports from the outside, we perform a port scan on the computer to be checked to find out which ports are open, which services monitor these ports, etc. Port scanning is usually performed by system administrators to check the security of the server, but unfortunately, it is also often used by malicious attackers to map the weak points of the selected target computer. On this page, we review the basic use of the nmap command.

Several services can run on a Linux operating system, especially on a more complex web server installation. These services communicate through different TCP (Transmission Control Protocol) or UDP (User Datagram Protocol) ports on the network interface. A listening port is a network port on which an application or process listens and acts as a communication endpoint. Checking ports is an important task from several points of view. On the one hand, for the sake of security, we must monitor the open ports and the communication on them, and on the other hand, we can also reduce the number of error possibilities that result from several similar services using the same port.

There are several ways to manage web servers and other servers remotely, of which SSH is the most common command line solution. The SSH protocol communicates over an encrypted channel between the server and the client. Like all similar communications, SSH transmits data through a specific port, which by default is the well-known tcp port 22. Since the function of this port is known to many people, it exposes the servers to regular attacks. This is usually avoided - or at least to reduce the number of attempts - by switching this well-known port to another, unknown port number, which can only be detected externally by port scanning, which is a more time-consuming task.
In this write-up, we will look at how to change SSH's well-known TCP port 22 to a unique port number to minimize the number of attack attempts via SSH.

.htaccess files are very useful accessories for the Apache web server, with the effective use of which we can solve many problems. However, in the case of a more complex server configuration, we need to pay attention to several things, otherwise we can easily generate Apache errors.
In this troubleshooter, we deal with redirects, where in certain situations we can end up in an endless redirect cycle, which eventually results in "AH00124: Request exceeded the limit of 10 internal redirects due to probable configuration error." leads to content errors.

With the help of LAMP systems, we can run dynamic websites on our server or even on our home computer. In this description, we will create a LAMP server on the Debian 11 (Bullseye) operating system, on which the following components will be installed: Apache 2.4.54, MariaDB 10.5.15, PHP 7.4 and phpMyAdmin 5.0.4, UFW firewall.