Latest Articles - Page 31

Configure SELinux port labels and booleans on Linux: read name_bind denials, add a port to http_port_t with semanage port, use -m when a port is already defined, and switch optional behaviour with getsebool and setsebool …

Manage SELinux modes and file contexts on Linux: getenforce and setenforce, ls -Z, matchpathcon, restorecon, semanage fcontext, AVC denials, and an httpd content fix without disabling SELinux.

Learn how Linux resolves hostnames through NSS, /etc/hosts, and DNS: use getent hosts and getent ahosts, dig and host, configure DNS servers and search domains with nmcli, and troubleshoot resolution failures.

Configure GRUB2 on RHEL with grubby and BLS entries: list kernels, set the default boot kernel, add or remove kernel parameters, use /etc/default/grub with grub2-mkconfig, and recover from bad boot arguments.

Schedule recurring and boot-relative jobs with systemd timers: pair a timer unit with a service unit, use OnCalendar and monotonic triggers, enable with systemctl, inspect list-timers and journalctl, and compare timers …

Install nfs-utils, export a directory from an NFS server, open firewalld for NFSv4, mount the share on a Linux client with vers=4.2, persist it in /etc/fstab, and troubleshoot common NFS errors.

Mount filesystems persistently with /etc/fstab using UUID and LABEL, validate with mount -a and findmnt --verify, and recover when a bad entry blocks boot.

Manage TuneD profiles in Linux with tuned-adm: list and read profiles, apply throughput-performance, check the recommendation, verify applied settings, inspect tuned.conf inheritance, and revert cleanly.

Reset a forgotten root password on RHEL 10 from the GRUB menu with rd.break, remount /sysroot, chroot, passwd, and SELinux autorelabel before you log in again.

Learn systemd targets as boot synchronization points: get-default, set-default, isolate multi-user or graphical, rescue and emergency mode, and one-boot overrides with systemd.unit=.

Reboot, power off and shut down Linux with systemctl and shutdown. Schedule or cancel reboots, notify users, and verify the new boot.

Install Flatpak on Linux, configure remotes, search Flathub or vendor catalogs, install update and remove sandboxed apps with flatpak run, permissions, and troubleshooting.

Learn Linux file permissions and ownership: rwx for files vs directories, chmod symbolic and octal modes, chown and chgrp, umask, SUID SGID sticky bit, and permission denied diagnosis.

Create and edit Linux text files with Vim, Nano, touch, redirection, search and replace, backups, and safe configuration edits from the command line.

Learn Linux stdin, stdout and stderr redirection with >, >>, 2>&1, pipes, tee, /dev/null, here documents, PIPESTATUS and pipefail.

Learn Linux command line basics: how the shell parses commands, navigate with paths, use quoting and expansion, find help with man and --help, and practice safe identity checks before you move on to file management and …

Understand the Linux filesystem hierarchy—what /etc, /var, /usr, and /home contain—and navigate with absolute and relative paths using pwd, cd, ls, file, stat, and find.

Manage Linux users and groups with useradd, usermod, userdel, groupadd, primary and supplementary groups, account defaults, and ownership checks.

Create LVM physical volumes, volume groups, and logical volumes, format with XFS or ext4, mount by UUID, extend a VG with vgextend, and remove layers safely.

Manage Linux processes with ps, pgrep, top, jobs, signals, and systemctl. Find high-CPU tasks, inspect process states, and stop processes safely.

Configure Chrony NTP on Linux, verify time synchronization with chronyc, force clock correction, troubleshoot sync problems, and optionally serve LAN clients.

Extend a logical volume with lvextend, grow PV capacity with pvresize or vgextend when the volume group is full, grow XFS with xfs_growfs or ext4 with resize2fs, and verify both layers.

journalctl reads logs collected by systemd-journald — kernel messages, service output, boot sessions, and syslog traffic in one queryable journal. Filter by unit, time, priority, boot, and process fields without hunting …

Install GNU flex and bison on Kali Linux as modern Lex and Yacc replacements, verify versions, compile a sample flex scanner, and remove the packages when the lab is done.

Build and install Pyrit 0.5.1 on Kali Linux from the JPaulMora GitHub tree with Python 2.7, fix GCC 14 compile flags, verify with pyrit list_cores and benchmark for authorized WPA lab work.

Install Gophish v0.12.1 on Kali Linux from the official GitHub release, configure config.json, start the admin UI on port 3333, and log in with the first-run password in an authorized phishing lab.

Install the Aircrack-ng suite and airmon-ng on Kali Linux with apt or a source build, verify SIMD support, list wireless interfaces, and enable monitor mode for authorized Wi-Fi labs.

Run Torshammer slow POST DoS tests on Kali Linux against local Apache or DVWA, compare DoS versus DDoS, and read curl timing before and during an authorized lab attack.

Hide and recover secret text inside JPEG and PNG images on Kali Linux with steghide and Stegosuite, compare OpenStego, and read capacity and encryption output in an authorized lab.

Analyze the public Cridex banking trojan memory sample with Volatility 3 and Volatility 2 on Kali Linux—OS profile, process tree, network connections, and reader_sl.exe extraction.