MAC Spoofing in Linux MAC stands for Media Access Control — a six-byte identifier (usually written as twelve hexadecimal digits) that uniquely identifies a network interface on a LAN. The Address Resolution Protocol (ARP) maps IP addresses to MAC addresses at layer 2. You might need to change your MAC address to: Bypass network access…
Excluding Packages from DNF/YUM Updates You may need to prevent certain packages from being updated during system maintenance—the kernel on production servers, or specific library versions you’ve carefully tuned. When you run dnf update or yum update, you want those packages skipped entirely. The solution is straightforward: add an exclusion to DNF or YUM’s configuration…
Install eCryptFS tools On Fedora/RHEL-based systems: dnf install ecryptfs-utils On Debian/Ubuntu: apt-get install ecryptfs-utils Load the kernel module modprobe ecryptfs To ensure the module loads automatically on boot, add it to /etc/modules-load.d/: echo “ecryptfs” | sudo tee /etc/modules-load.d/ecryptfs.conf Create directories You’ll need two directories: one for encrypted storage (.private) and one as the mount point…
Setting Up Xen Dom0 on Fedora Xen remains a production hypervisor for enterprise deployments (AWS EC2, Citrix Hypervisor), though KVM has become the default for most Linux distributions. If you’re deploying Xen in 2026, you’ll likely be working with recent stable releases rather than the legacy versions covered in older guides. This guide covers building…
Using rsync for Home Directory Backups rsync is a reliable choice for backing up your Linux home directory, especially when dealing with large files and incremental changes. Unlike git (which struggles with files >5GB), rsync efficiently handles large files and only transfers what’s changed on subsequent runs. Basic Backup Command The fundamental syntax is straightforward:…
Capturing Desktop Video on Linux with ffmpeg ffmpeg is the de facto tool for desktop recording on Linux. It can capture your X11 or Wayland display and encode directly to MP4, WebM, or other formats without requiring intermediate files. Basic X11 Screen Capture For X11-based desktops (KDE Plasma, XFCE, i3, etc.), use the x11grab input…
Generate SSH Key Pair If you don’t already have a key pair, use Ed25519 — it’s faster and more secure than RSA: ssh-keygen -t ed25519 -C “your_email@example.com” For older systems that don’t support Ed25519, RSA with 4096 bits still works: ssh-keygen -t rsa -b 4096 Keys are stored in ~/.ssh/ by default: id_ed25519 (private) and…
Installing akmod NVIDIA Driver on Fedora Installing the NVIDIA driver on Fedora via akmod (automatic kernel module) is the cleanest approach when using RPM Fusion. The driver rebuilds automatically whenever the kernel updates, saving you manual reinstalls. Prerequisites First, verify your GPU is supported. Check the NVIDIA driver support matrix for your hardware. Most consumer…
Sending Email via Gmail SMTP with mailx/s-nail The mailx (or s-nail on modern distributions) command remains useful for scripted email delivery, particularly when you need to send alerts or notifications automatically. Gmail’s SMTP service works well for this, though it requires TLS authentication and specific configuration. Prerequisites Most Linux distributions include mailx or s-nail by…
Network Configuration on the Gateway A Linux box serving as a network gateway needs two network interfaces: eth0: Connected to the local network (LAN) with IP 192.168.0.1 eth1: Connected to the upstream network (Internet) with IP 198.51.100.1 The goal is to allow clients on the 192.168.0.0/16 network to route traffic through this gateway to reach…
Control or Disable SELinux in Fedora and RHEL-based Systems SELinux provides mandatory access controls that catch security violations most firewall and file permission rules miss. Before disabling it, exhaust other options — SELinux warnings often reveal real security problems worth understanding. That said, there are legitimate reasons to adjust SELinux: testing application behavior without policy…
Guake: A Drop-Down Terminal for GNOME Guake is a drop-down terminal emulator for GNOME that brings the Quake-style console experience to Linux desktops. When you press a hotkey (F12 by default), a terminal slides down from the top of the screen. Press it again and it retracts. It’s fast, minimal, and designed purely around keyboard…
Setting Up a SOCKS Proxy Over SSH A SOCKS5 proxy tunneled through SSH provides encrypted communication between your client and a remote server. This is useful for bypassing network restrictions, securing connections on untrusted networks, or routing traffic through a trusted server. Basic Setup The simplest approach uses SSH’s dynamic port forwarding with the -D…
Backup Strategy for Xen File-backed DomU Xen remains in production use (AWS EC2, Citrix Hypervisor), though KVM has become the standard Linux hypervisor. This guide covers automating backups for file-backed Xen virtual machines. The approach adapts to other hypervisors like KVM with minimal modification. Architecture and Prerequisites The backup system assumes: Virtual machines stored in…
Running Jobs in the Background When you need to start long-running commands while continuing to work in the shell, run them in the background. Bash and other modern shells maintain a job list and allow you to switch jobs between foreground and background execution. Only one job can run in the foreground at a time….
Setting Default Playback Parameters in mpv mpv inherits much of MPlayer’s command structure, but with modern improvements for hardware acceleration, Wayland support, and codec handling. Here’s how to configure default startup volume and playback position. Configuration File Edit ~/.config/mpv/mpv.conf and add your defaults: volume=80 start=10 The volume parameter sets initial volume as a percentage (0–100)….
Understanding lftp Data Connection Hangs When using lftp to connect to FTP servers, you may encounter a stall with “Making data connection” after logging in: < — 227 Entering Passive Mode (xx,xx,xx,xx,xx,xx) —- Connecting data socket to (yy,yy,yy,yy) port zz `ls’ at 0 [Making data connection…] The connection hangs indefinitely, though other clients like FileZilla…
Remote Desktop Access via VNC Through SSH Tunnel Accessing a remote desktop environment on a Linux server securely requires proper tunneling. While SSH X11 forwarding works for single applications, VNC provides a full graphical desktop session. By combining VNC with an SSH tunnel, you encrypt all traffic and can work around firewall restrictions that only…
MPlayer is largely unmaintained; mpv is the actively developed fork that handles 95% of these commands with compatible bindings. That said, if you’re still running MPlayer or need legacy support, here’s what you need to know. MPlayer uses a fully configurable keyboard control layer. Most of these shortcuts work in mpv as well, though some…
Flushing DNS Cache on Linux DNS caching helps reduce lookups but sometimes you need to clear it after DNS changes, certificate updates, or to troubleshoot resolution issues. Modern Linux with systemd-resolved Most contemporary Linux distributions use systemd-resolved as the default DNS resolver. Flush the cache with: sudo systemctl restart systemd-resolved Or use the resolvectl command:…