In the world of Linux and Unix-like operating systems, the “Permission Denied” error is a common occurrence that stumps many users, particularly when encountered in situations where file permissions seem to be correctly set. One less obvious but significant cause of this error is the `noexec` mount option. Understanding how this option works is key …
Linux
Ever encountered the cryptic message “Remote Host Key Has Changed” while connecting to a server using SSH (Secure Shell)? This seemingly technical error notification actually serves as a vital security safeguard. Each server in the SSH world has a one-of-a-kind identifier called a host key, similar to a digital fingerprint. When you connect for the …
In Linux, getting the SSH host key fingerprint is crucial for verifying the identity of an SSH server before establishing a connection. Here are the methods to retrieve the host fingerprint: Method 1: Using ssh-keygen Local Server: To find the fingerprint of a local SSH server’s host key, use: ssh-keygen -lf /etc/ssh/ssh_host_rsa_key.pub The -l option …
When connecting to an SSH server, especially for the first time, users often encounter a security prompt. This prompt plays a crucial role in the SSH connection process, ensuring the security and authenticity of the server being connected to. The authenticity of host ‘howtouselinux (10.254.175.51)’ can’t be established. ECDSA key fingerprint is SHA256:PgyFiC7Su7BiFBO1Sn8493MMz8/PE+2fJMI/mFfBy9M. Are you …
The error message bash: TMOUT: readonly variable indicates that the TMOUT variable has been set as readonly, which prevents you from changing its value in your current session. This is usually done for security reasons, often in a global configuration file, to enforce automatic logouts for idle sessions. To fix this and change the TMOUT …
Addressing SSH auto-logout issues often involves configuring two key settings: the TMOUT shell variable and the StopIdleSessionSec setting in /etc/systemd/logind.conf. Each plays a distinct role in session management and inactivity handling. TMOUT Variable: A Bash shell setting that defines the maximum idle time before automatic logout. It is crucial for users experiencing undesired SSH disconnections …
Introduction Linux stands as a bastion of network management, offering a suite of powerful tools and commands for effective network administration. Among these, understanding and managing network interfaces is a crucial skill for any Linux system administrator. Network interfaces in Linux are the points through which devices communicate with external networks. This article delves into …
Introduction When you browse the internet, you are actually accessing different websites by their domain names. However, your computer doesn’t understand domain names, so it needs to translate them into IP addresses. This is where Domain Name System (DNS) servers come into play. A DNS server is responsible for translating domain names into IP addresses. …
Alternate row color shading in Excel, also known as “zebra striping,” refers to the practice of formatting rows in a spreadsheet so that adjacent rows have different background colors. This visual distinction makes data easier to read and scan, especially in large spreadsheets with numerous rows of information. In this article, we will introduce 3 …
On a Linux system, TCP ports in a reserved range (typically less than 1024) can only be bound by processes with root privilege. If we’re trying to bind a port in a Linux environment less 1024, we will receive a “Permission denied” error. Listen tcp :80: bind: permission denied So we should do either: Reason …