Learn Linux Daily!

Learn how Linux uses standard input, output, and error data streams, and master redirection and piping to connect commands and build powerful pipelines.

Learn to pipe commands in the Linux shell, redirect outputs to files, and pass data through pipelines using cut and xargs to extract the day of the week.

Create a hidden bash aliases file in your home folder, define a command alias, and use it in pipelines to save outputs to full date txt and short date txt.

Learn to create files and folders using touch and mkdir, add content with echo, handle spaces, and generate many files with brace expansion for efficient project organization.

Learn to use wildcards and regular expressions with the LSE command to list directories and pattern-match files using star, question mark, and square brackets, with case sensitivity.

Learn how to delete files and folders in Linux using rm, with relative and absolute paths, wildcards, brace expansion, and interactive prompts for safety.

Learn to copy and move files and folders with cp and mv, including recursive copies, renaming, and using wildcards and destinations such as desktop and home directory.

Learn to edit files with nano from the command line by creating diary.txt, saving, reading files, searching, replacing, cutting and pasting, and basic customization like spell checking.

Learn how the locate command searches a system database with patterns, case sensitivity, and limits, and how to update the database using sudo update-db with existing and follow checks.

Master the find command to search by name, type, and size, control depth with max depth, and execute actions on results using -exec and -ok.

Use cat to read and concatenate files, apply wildcards, and redirect output; then reverse with tac and rev, or page with less, head, and tail.

Learn Linux daily teaches practical sorting with the sort command, including alphabetical, numerical, and column-based sorts, reverse and unique options, and human-readable outputs.

Learn how the grep command searches input for lines containing text, counts matches, and uses options like -i and -v to refine case-insensitive results across files.

Create tarballs to archive and organize files in Linux, then compress with gzip or bzip2 to reduce size, and perform a one-step tar with compression for backups.

Schedule tasks with cron by editing cron tabs and specifying minutes, hours, days, months, and weekdays. Learn to automate commands and backups with scripts and log results.

Explore the Linux file system hierarchy from the root directory to /home, /boot, /var, and /etc, learn absolute and relative paths, and gain essential navigation concepts.

Master APT package management to keep your Linux system up to date by updating caches, upgrading software, and installing from repositories, including purge, auto remove, and clean commands.

Explore how the apt cache powers package discovery and information retrieval using apt cache search and apt cache show, and inspect /var/lib/apt/lists to understand offline access.

Explore Ubuntu repositories as digital libraries, including main, universe, restricted, and multiverse, and learn how apt manages packages and updates to keep your system secure.

Explore core utils from the dot org site, download stable sources, unpack xz archives, inspect ls.c in crc, then configure, compile, and install with make and sudo make install.

Acquire hands-on skills to manage Linux packages with apt: update and upgrade caches, install and purge software, auto remove dangling dependencies, and clean archives for a lean system.

Master setting up a local Linux development environment with a LAMP stack, configure Apache virtual hosts, edit the hosts file, and manage MySQL and PHP testing.

Explore how a Unix-like system supports multiple users and manages access with accounts and groups, using /etc/passwd, /etc/group, and commands such as useradd, id, and su.

Explore Linux file permissions, including owner, group, and others, with read, write, and execute bits. View them with ls -l and manage with chmod, chown, and chgrp.

Learn how mode bits extend Linux file permissions, including sticky, capital X, set UID and set GID, and how execute rights differ for files and directories, with practical chmod examples.

Master Linux user and group administration, from creating and deleting users and groups to setting ownership and permissions, umask, ACLs, setuid/setgid, and sticky bits.

Explore how the OSI model's seven layers enable cross-network communication, from application layer protocols to physical transmission, including TCP and UDP, IP addressing, routing, and media access control.

Understand what an IP address is and how devices connect on the internet. Compare IPv4 and IPv6, dynamic and static IPs, and the role of DNS servers.

Explore how IP datagrams traverse networks, comparing IPv4 and IPv6, and decode header fields like version, header length, TTL, protocol, checksum, and fragmentation.

Identify the physical components of a computer network—endpoints, NICs, media, connectors, switches, and routers—and explain how data travels to internet services and servers using DNS and IP addresses.

Understand how a network interface card enables wired and wireless connections for LAN data sharing, and how network protocols govern packetized data, including TCP, UDP, HTTP, FTP, R.P and ICMP.

Explain how physical (MAC) addresses deliver frames on a LAN and how logical (IP) addresses route packets across networks via routers; transport ports ensure data reaches the correct process.

Explore how interfaces connect hosts and routers to the internet, and how IPv4 addresses, 32-bit dotted decimal notation, and subnet masks (CIDR) define subnets and network prefixes.

Compare packet switching and circuit switching, detailing store-and-forward delays, queuing, and packet loss. Explain how link capacity sharing, bandwidth, and routing determine efficiency and real-time suitability.

Explore how arp translates an ip address to a mac address, enabling ethernet data transfer, and examine arp requests, arp replies, and dynamic arp table updates with a gateway router.

Understand how the Dynamic Host Configuration Protocol (DHCP) automatically assigns IP addresses via a DHCP server, using Discover, Offer, Request, and Acknowledgement, with subnet mask, gateway, DNS, and lease renewal.

Learn how the domain name system translates domain names to IP addresses, with DNS resolvers contacting root, TLD, and authoritative name servers and using cache to load websites.

Understand how firewalls, software, hardware, and hybrid control traffic using packet filtering and proxy methods to shield networks from internet threats. Learn the role of ACLs, ports, payload, and limitations.

Learn Cisco router CLI through hands-on hardware basics, console access, interface configuration, SSH authentication, banners, and saving running configurations to startup config for hands-on practice.

Explore how ethernet evolved from bus and hubs to switches, learning mac addresses, reducing collision domains, and applying store-and-forward, cut-through, and fragment-free switching.

Explore VLAN fundamentals as a layer two boundary that segments a network into separate broadcast domains, linking VLANs with a router for inter-VLAN communication and a subnet per VLAN.

Learn how to connect switches using VLAN trunking and tagging, implementing 802.1Q trunking (and ISL), configuring access and trunk ports, voice VLANs, native VLANs, and router-on-a-stick setups.

Learn how access control lists filter network traffic with ACEs that permit or deny packets. Explore standard and extended ACLs, wildcard masks, and applying ACLs to interfaces.

ARP resolves an IP to a MAC address by broadcast request and unicast reply; it uses a dynamic cache and includes reverse ARP and gratuitous ARP for changes.

Discover how DHCP dynamically assigns IP addresses through discover, offer, request, and ack, set lease times and options like router, DNS, and domain name, and use relay for multi-segment networks.

Learn to configure DNS on Windows Server using forward lookup zones, authoritative and non-authoritative responses, and A, CNAME, and MX records; grasp recursive vs iterative lookups and TTL caching.

Configure and analyze static routes, default routes, and routing tables to understand how routers forward packets via next-hop addresses and gateways of last resort.

Learn dynamic routing with RIP, master longest prefix match and administrative distance, and use floating static routes to provide backup paths when primary links fail.

Explore rip, a classic distance-vector dynamic routing protocol, learn rip v2 classless updates, network statements, auto summary, authentication, passive interfaces, and convergence through practical labs.

Explore NAT basics and how private inside local addresses become public inside global addresses. Configure static and dynamic NAT, PAT, port forwarding, and port overload to enable bidirectional internet access.

Discover why accurate time matters for logs, security, and scheduling, and configure NTP clients and stratum zero to three time sources—from internal to internet servers—for synchronized clocks.

Monitor network devices with snmp by polling at intervals and using traps for events. Learn the mib hierarchy and oids, and compare snmp versions 1, 2c, and 3 for security.

Compare Linux and Cisco IOS CLI commands for creating, listing, and deleting files and directories using mkdir, pwd, dir, rm, and delete, with dash and forward slash options.

Explore how devices generate logs and use an external UDP syslog server for cross-vendor visibility. Configure facilities, severity levels, timestamps, and Kiwi to centralize log collection.

Explore how spanning tree prevents layer two loops using BPDUs, elects a root bridge, and blocks links, with VLAN variants like PVST and MST.

Investigate IPv4 addresses, their 32-bit structure and classful blocks, then apply CIDR and NAT to conserve public space while using private IP ranges.

Learn to view Linux network interfaces with IP link and IP address, identify the loopback and Ethernet interfaces, and use if up/down to manage interface state.

Master netstat and ss to inspect active network connections, ports, and routing tables, with non-root and root access differences, and learn how to view kernel interfaces and overall network statistics.

Learn to view and set ip addresses on Slack and CentOS 7 with ifconfig and ip addr, make temporary and permanent changes, and manage routes with route.

Map IP addresses to MAC addresses with ARP, a datalink layer 2.5 protocol enabling initial communication. See ARP requests, replies, and cache updates that support ongoing conversations.

Explore how ICMP enables network diagnostics with the ping utility, focusing on echo request and echo reply (types 8 and 0), and tcpdump-based packet capture.

Explore how IP addresses identify hosts and locate them on the network, covering IPv4 and IPv6 structures, network prefix, host identifier, and subnet routing via a gateway.

Explore how a subnet mask divides an IP address into network and host parts, explains classful addresses (A, B, C) and default masks, and shows how subnetting reduces broadcast traffic.

Learn how Linux bonding combines multiple interfaces into one bonded interface to boost throughput and provide redundancy. Explore bonding modes from balance-rr to balance-alb, including 802.3ad, with setup steps.

Learn how interface teaming replaces bonding in CentOS 7, using the Team DX daemon and runners like broadcast, round robin, active backup, and load balance to manage traffic.

Install ntpd on CentOS, disable chrony, set driftfile and iburst servers, enable firewall rules, verify with ntpq, then sync an Ubuntu client and compare ntp output.

Configure ipv6 addresses on two machines using network manager nmcli and verify connectivity with ping6. Learn key ipv6 commands to view addresses, neighbors, routes, and traces on local interfaces.

Configure chrony-based NTP on Red Hat 8 servers and clients, enable firewall rules, start services, verify time with chronyc, and manage DNS, hosts, and network connections with nmcli and nmtui.

Explore the OSI bottom layers, from physical to network, and learn key devices (modems, hubs, switches, wireless access points, routers) and security features.

Create Linux partitions on two drives, form physical volumes, merge them into a volume group, and build logical volumes with a shared file system.

Create physical volumes on sdb1 and sdc1, form vg pull, create lv stuff (3 gb) with a filesystem, then extend to 11 gb and resize the filesystem.

Learn to create and manage a simple systemd service: write a pointless.service with exec start, enable and start it, monitor logs, and configure options like restart, working directory, and environment.

Learn to extend and reduce a linux volume group by creating and adding physical volumes, moving extents, and verifying changes with vg display, including replacing failing or slower hardware.

Learn how Samba enables Linux and Unix to share files and printers with Windows clients using the SMB protocol; configure /etc/samba/smb.conf, set global options, share definitions, and test with testparm.

Learn how to create standard partitions with fdisk on a block device, format them, update /etc/fstab with uuid or label, and mount; explore swap, lvm, Stratis, and zfs.

Explore how the tuned profiles optimize throughput and latency on RHEL seven, showing real-time adjustments, persistence after reboot, and jitter reduction for network workloads.

Master performance tuning through systemd service management, cron scheduling, grub boot configurations, tone profiles, yum modules, and tmpfiles for efficient Linux administration.

Learn to create and run a bash script by adding a shebang to reference /bin/bash and using mkdir, cd, touch, and ls to automate tasks on Linux.

Learn to write bash scripts, create and name hello_world.sh, use the shebang, edit in vi, set executable permissions with chmod, and run scripts from their directory.

Learn to define and echo shell script variables in a hello world example, using a and b with values 640 and 7.2, and print via echo $a and echo $b.

Explore how to perform arithmetic in bash scripts by declaring A and B, computing sum and difference with the $((...)) syntax, and echoing results.

Explore bash if conditions and arithmetic relational operators like less than, greater than, equal, and not equal. Apply numeric and string comparisons with read inputs, echo, and if-else-elif blocks.

Explore how to define and reuse functions in shell scripts, capture user input, and pass arguments to functions, with practical examples like a square calculator and conditional argument checks.

Explains bash loops with for ranges and backticks for command output, and introduces while loops driven by conditions. Builds a simple menu with user input, using if-elif-else and exit.

Learn how to declare and initialize arrays in Bash, access elements by index, print all elements, and count array elements using Bash's array syntax.

Design a bash script that defines functions to get the IP address, system time, and user/host information, presents a menu, reads user input, and executes actions or exits.

Explore awk, a text-processing toolset that processes files line by line using patterns and actions, printing fields, using -f, begin and end blocks, and custom field separators.

Master awk with practical examples, from pattern matching to regular expressions and printing fields, including skipping headers. Use real files like /etc/passwd to extract user and login data.

Learn how to use sed to search and print matching lines, substitute text, print line numbers, define line ranges, and perform in place edits with backups.

Explore bash scripting from basics to advanced topics, including executing scripts, input and output, conditionals, loops, arrays, functions, file operations, and text processing with grep, awk, and sed.

Learn to manage SELinux on Linux by switching between enforcing and permissive modes and applying permanent settings in /etc/selinux, configure Apache with a document root, and open ports with firewalld.

Manage Linux firewalls with Firewall DX on Red Hat seven and CentOS seven. Learn to define zones, open ports and services, and persist rules across reboots.

Master rich rules in firewall dx to configure logging, masquerading, port forwarding, and rate limiting, and learn the command syntax and rule processing order.