The SSH protocol operates on port 22 by default. In order to accept incoming connections on your Red Hat 7 Linux SSH server, you will need to ensure that port 22 is allowed through the firewall. This will involve opening the port in firewalld, the default firewall interface for Red Hat.
The conventional way used to change the runlevel with
/etc/inittab has become obsolete with Red Hat Enterprise Linux version 7. As a result, any Linux system using systemd system management daemon now relies on the
systemctl command to change runlevel – or, to be more precise, to change the target. Therefore any edits to the
/etc/inittab file will not take effect on RHEL 7.
The hostname of your Red Hat Enterprise Linux system is important because it’s used to identify the device on a network. The hostname is also shown in other prominent places, such as in the terminal prompt. If you have not bothered to change the hostname yet, your system probably bears the default
localhost.localdomain name, which is not very helpful.
When running an Apache web server on Red Hat Enterprise Linux, you may encounter the error
AH00557: httpd: apr_sockaddr_info_get() failed or
AH00558: httpd: Could not reliably determine the server's fully qualified domain name when trying to start the service. In this tutorial, we will look into the cause of this error and give you a solution for fixing it.
You may receive a
There are no enabled repos error message when trying to install system updates on a fresh Red Hat Linux install. This occurs when you have not enabled your RHEL subscription. In this tutorial, we will take you through the step by step instructions to register your RHEL subscription, enable the package manager, and finally install updates and remedy the error message for good.
firewalld is the default firewall on Red Hat Enterprise Linux, and it’s enabled by default, but it’s possible to Redhat disable firewall, and you’ll also see how to check firewall status in Linux. Normally, there should not be a need to disable the firewall, but it may be quite handy for testing purposes or other scenarios.
SELinux, which stands for Security Enhanced Linux, is an extra layer of security control built for Linux systems. The original version of SELinux was developed by the NSA. Other key contributors include Red Hat, which has enabled it by default in their own RHEL and its derivative Linux distributions, including CentOS 7.
The purpose of this tutorial is to enable auto login on GNOME GUI and the KDE Plasma desktop environment on CentOS Linux system. If you are using CentOS and getting tired of needing to provide your password every time your computer boots up, or goes back to the lock screen, then enabling auto login will save you some time and frustration.