Administration of Red Hat Enterprise Linux

Navigate the Linux file system using absolute and relative paths, the current directory, and identify regular, directory, executable, symbolic link, and device files with file and ls -la.

Create files with touch and text with cat or vi, create directories with mkdir and -p, and list or view contents using ls, ll, more, less, head, and tail.

Learn how to copy, move, rename, and remove files and directories with cp, mv, and rm, using -i prompts and -r for recursive directory operations.

Explore ext file system attributes and commands lsattr and chattr to enable append, immutable, and synchronous behavior, governing deletion and modification.

Master the find command to locate files and apply actions with dash exact, changing permissions from 777 to 644, deleting files, and filtering by type, name, owner, and emptiness.

Discover how to locate files with the find command by modification time, access time, and size, using examples for 7 days, last hour, and size filters.

Learn to use the locate command (mlocate) on Red Hat Enterprise Linux by installing it, updating the database, and finding files with options like -n, -c, and -i.

Learn to find files larger than 100 megabytes and produce a long listing saved to /tmp/big_files using the find command with size and exec options, plus megabyte size notation.

Learn to view and interpret file permissions with ls -l and ls -lg, distinguish user, group, and others, and use chmod to set read, write, and execute rights.

Discover how to manage Linux file and directory permissions by creating items, applying chmod settings (0700, 0711, 0777, 0000, 644), and using recursive, umask, and ownership commands to control access.

Master group management in Red Hat Enterprise Linux by creating groups with groupadd, assigning users with usermod, and applying setgid on the opt-myproject directory to streamline project file collaboration.

Learn Vim basics by switching between insert and normal modes, navigating with h j k l and word commands, using search, percent, and visual mode for editing.

Master vim basics: open and edit with vim, switch between insert and command modes, navigate with h j k l, and save or quit using write and quit commands.

Master Vim’s built-in help system by using :help to access topic guides, navigate with tab-completion, and quickly exit back to your editing session.

Practice creating and editing a new file in vim by opening text1.txt, entering insert mode, typing text, and saving your changes with wq.

Navigate vim with h j k l and zero or dollar for line edges. Edit with i, a, c, d; cc, dd, and yy, and tilt case.

Master Vim navigation by scrolling with ctrl f/b/d/u, moving by line and screen, using z commands to keep the cursor, and searching with / and n for multiple results.

Open vim to a specific line or pattern, or in read-only mode, and recover edits after a crash; save and exit with :w, :q, :wq, or :x.

Open multiple files with vim -o to create a horizontal split. Split vertically with :vsplit, navigate each buffer, and set last status=2 to show status lines in all windows.

Learn to switch between two open files in Vim by enabling the mouse with set mouse=a and using ctrl-w to move between session windows, plus keyboard navigation.

Master basic Vim navigation by switching between normal and insert modes, using h j k l for cursor movement, and searching with / and N, and exiting with Escape.

Install vim on Linux, macOS, and Windows, then practice navigation (h, j, k, l, 10J, 20K, W, B, $, 0), enter insert mode with I, and exit with :q.

Learn essential Vim editing and navigation commands, including moving to screen and document positions, text insertion, copying, deletion, and undo/redo, for efficient Linux editing.

Practice vim navigation with hands-on exercises: jump between paragraphs with curly braces, and move with h, m, l and 0, $, gg, G.

Master vim copy and insert techniques, using y, yw, and yyy with p to paste, undo with u, and read files with :read; practice duplicating, deleting, and changing lines.

Master Vim fundamentals through modal navigation, including normal and insert modes, efficient movement, searching, editing, yanking, and search-and-replace, with tips for macros and multiple-file work.

Explore Vim from basic file creation to advanced text manipulation, with navigation, deletion, and yanking, and efficient editing. Use visual mode, substitutions, and window and buffer management.

Practice Vim text editing by creating a file, entering insert mode, pasting content, deleting and undoing changes, and editing words, lines, and blocks, including commenting lines with a hash.

Practice advanced Vim editing in exercises, reorder sections, cut and paste blocks, and annotate scripting languages for web development and system administration.

Practice editing in vim by deleting lines, substituting scripting with programming, and adjusting indentation; learn search, replace, yank, paste, and text selection techniques across TypeScript, JavaScript, and Ruby sections.

Master advanced vim techniques for editing, navigation, and multi-window workflows, including opening at specific lines, read-only mode, dot command, substitutions, and saving copies across files.

Navigate and edit multiple files in Vim by opening several buffers, switching between files with next and previous, using horizontal and vertical splits, editing new files, and saving with wqa.

Learn to manage multiple files in Vim by opening three config files in split windows, using diff split to compare, and applying batch edits across buffers.

Use grep to search for words or phrases in a file, and wc to count words, characters, and lines, with -n, -c, -v, -w, -m, and -l.

Explore how the cat command reads standard input from the keyboard, writes to standard output, and uses redirection operators to create, append, and concatenate files in Red Hat Enterprise Linux.

Learn to use pipes to streamline tasks by connecting who to sort and wc -l, producing a sorted user list and a login count without temporary files.

Explore processes in a hierarchical parent–child structure with pids and lifecycles, daemons, and how to monitor them with ps and top via the /proc view.

Explore linux processes and jobs, including foreground and background execution, suspend with ctrl-z, manage with jobs, fg, and bg, and terminate with kill and ps to locate pids.

Learn how to use the Linux top command to view all running processes, monitor CPU, memory, and swap usage, and customize sorting and display options.

Learn to locate pids with pidof and pgrep, list processes by user or group with ps, and understand the five process states: running, sleeping, waiting, stopped, and zombie.

Explore how process niceness, defined by the nice value from -20 to 19, affects scheduler priority, and learn to view and adjust it with ps, top, monitor, nice, and renice.

Learn how to control Linux processes with signals, using kill and pkill to send signals like SIGHUP, SIGINT, SIGTERM, and SIGKILL for graceful or forced termination and configuration reload.

Change your password with the passwd command, then explore shell and environment variables, assign and access shell variables, and understand how PATH controls command lookup.

Explore essential linux special characters, from asterix and dollar to brackets and braces, and master common command line keystrokes like ctrl-b, ctrl-f, ctrl-a, and ctrl-e.

Learn to combine commands using chaining operators in Linux, including background execution with &, sequential runs with ;, and conditional and negation with &&, ||, and !.

Learn to use sed for search and replace with global g and write results to files, and harness awk to parse lines and extract fields from /etc/passwd for system administration.

Master advanced set command usage for Linux text operations, including printing specific line ranges, substituting words with case-insensitive options, and inserting blank lines via pipelines.

Perform exit, reboot, power off, and shutdown on Red Hat Linux, using options like -h, -p, -r, and timed schedules, while understanding root privileges and authentication requirements.

Learn how bash history works, including startup and initialization files, history loading from ~/.bash-history, and controlling history with HISTSIZE and HISTFILESIZE, plus commands to view, edit, and search history.

Learn to view, create, and manage shell aliases using the alias and unalias commands, make per-session or permanent aliases via .bashrc, and switch users to see alias behavior.

Learn to monitor a command's changing output with watch, adjust refresh with -n, highlight differences with -d, and watch file growth and log updates.

Learn how to gain administrative privileges on red hat linux using sudo and su, configure sudoers with visudo, and review sudo activity in /var/log/auth.log.

Master scheduling one-time and recurring tasks with atd and cron-d, including job submission, time formats, and access control via allow and deny files.

Explore how Red Hat uses rpm and yum to install and manage rpm packages, with emphasis on package metadata, dependencies, naming conventions, and the central package database.

Master rpm package management using key query options (-q, -qa, -qc, -qd) and install options (-F, -I, -U, -H, -V) to manage packages and dependencies.

Learn to manage rpm packages: install, upgrade, freshen, override, and remove from local or remote sources; handle dependencies, extract files with rpm2cpio, and verify integrity with MD5 and GPG keys.

Learn to view and verify GPG keys using rpm commands and rpm -V to compare package attributes such as owner, group, permissions, size, and digest, with practical examples.

Manage Linux packages with yum, the rpm front-end, configuring repositories, caching, and logging via /etc/yum.conf and yum-config-manager to ensure secure, consistent Red Hat updates.

Manage hostnames in Red Hat Enterprise Linux. Learn what a hostname is, where it’s stored, how to view it, and set it permanently with hostnamectl, /etc/hostname, and update /etc/hosts.

Explore IPv4 addressing fundamentals, static and dynamic addresses, dot-decimal notation, subnet masks, and using ping, traceroute, and tracepath for troubleshooting.

Use the ip command to inspect interfaces with ip link show, view addresses with ip address show, and add addresses with ip addr add on Red Hat Enterprise Linux.

Validate and troubleshoot network configuration using basic utilities like ip, ip route, and ss, inspecting interface details, IPv4/IPv6 addresses, routing, connectivity with ping and traceroute.

Configure networking with the Network Manager command line interface nmcli, and manage devices and connections, including DHCP and static configurations, using nmcli-con-show, nmcli-dev-status, and nmcli-con-add.

Learn to validate network configuration on Red Hat Enterprise Linux by using ip commands to inspect interfaces, addresses, and routing, test connectivity with ping, and monitor sockets in hands-on exercise.

Learn to configure Red Hat network settings by editing ifcfg files and using nmcli, including static and dhcp addresses, dns, and a hands-on exercise with eth0.

Configure two static ipv4 addresses on a network interface using nmcli and ip tools, set gateway and dns, manage autoconnect, update hosts, and reboot to verify connectivity.

Create a Red Hat Enterprise Linux 9 virtual machine with Hyper-V or other hypervisors, install the server with GUI, configure networking and user access, and register for development use.

Register Red Hat Enterprise Linux 9 from the command line to access updates, support, and repositories, then attach, verify, and manage subscriptions with subscription-manager commands.

Gain superuser access in Red Hat Enterprise Linux with su and sudo, switch to root or other users, and understand dash versus non-dash shells and wheel group privileges.

Demonstrate gaining superuser access with sudo and su, compare non-login and login shells, and practice managing home and path variables while running commands as root and a normal user.

Create, modify, and delete Linux user accounts using useradd, usermod, and userdel, set passwords with passwd, switch to root with sudo su -, and verify entries in /etc/passwd.

Create, modify, and delete groups with groupadd, groupmod, and groupdel; use -g or -r to assign system gids, and use usermod to set primary or supplementary groups.

Create operator and admin supplementary groups, add users to these groups, verify memberships with id and /etc/group, and grant sudo privileges via /etc/sudoers.d/admin.

Learn how Red Hat Enterprise Linux manages user passwords with etc.shadow, includes password aging and expiration, and uses account controls like locking and no-login shells.

Practice managing user passwords by forcing first-login changes, setting 90-day password aging, and expiring accounts after 180 days, using sudo, ch, date, and vim.

Practice managing local users and groups in red hat enterprise linux. Create a consultants group with gid 40000, add consultants, and configure sudo and account expiration and 15-day password policies.

Practice securing Linux root access by checking root status, using su and sudo, and enforcing current security best practices on a live system, including sudoers configuration in /etc/sudoers and /etc/sudoers.d.

Lock the root account using sudo passwd -l root and verify it is locked. Use sudo for privilege escalation and harden ssh by disabling root login.

Create a restricted service account and a sudoers.d profile granting specific commands without a password on all servers, then test systemctl and journalctl access.

Build a role-based access control system using groups, create web, db, and backup admin groups, provision users, and configure group-based sudoers rules for service management.

Configure sudoers permissions and ownership to root, validate role-based access controls for web, db, and backup admins, and verify allowed commands and service management.

Explore advanced sudoers configurations to harden Linux security with input and output logging, per-user defaults and command aliases, routing logs to /var/log/secure and /var/log/audit.log, with strict timeout and password rules.

Examine environment security and sudoers to prevent privilege escalation by enforcing a secure path, environment reset, and removal of dangerous variables like ldpreload.

Explore environment variable testing and attack mitigation by demonstrating sudo env usage, LD_PRELOAD risk, and securing the path with sudoers rules to prevent privilege escalation.

Explore pseudo session management for security in shared environments and configure timeouts with a sudoers.d file. Define default timeouts for quick, long, and secure sessions and test with password prompts.

Analyze effective sudo policies using sudo -l to view user rights, defaults, and group-based rules. Debug command execution with -u and -L, and interpret policy messages.

Clean up test sudoers configurations by removing test users and groups, archiving sudoers files, and verify integrity with visudo -c.

Learn sudoers best practices and how to set up a configuration repository with service, web admin, and environment security role files to enforce least privilege.