This beginner course builds a command-line workflow for understanding and troubleshooting Linux networking. Through six guided labs, you will inspect interfaces and routes, test reachability, query DNS, identify listening sockets, retrieve HTTP content, and make a temporary address change on a prepared interface.
The final challenge asks you to collect evidence from loopback connectivity, a local web port, and interface configuration, then decide whether a simulated outage is caused by the network path or the service.
What You Will Learn
- Inspect link state and IPv4 addressing with
ip linkandip addr - Test loopback, gateway, and external IP reachability with limited
pingrequests - Read packet-loss summaries and distinguish basic path availability from instability
- Perform forward and reverse DNS lookups and inspect
/etc/resolv.conf - List TCP and UDP listeners with
ssand associate privileged port output with processes - Download local HTTP content with
wget, inspect headers withcurl -I, and rename output withcurl -o - Add, verify, and remove a temporary IPv4 address on the prepared
labex0interface - Diagnose a reachable host with a closed application port and record the service-level cause
Who This Course Is For
This course is for Linux beginners, support technicians, and aspiring system or DevOps administrators who want a practical first-line networking toolkit before moving to routing, firewall, or service configuration.
Prerequisites: Basic terminal navigation, command execution, pipes, grep, and output redirection; no prior network-administration experience is required.
Learning environment: A provided Ubuntu-based LabEx terminal with loopback and external connectivity checks, a local HTTP server, a prepared labex0 interface, and a controlled troubleshooting scenario.
Frequently Asked Questions
How is the course structured?
Six labs provide guided practice. The seventh item is a troubleshooting challenge where you save ping, curl, and ip addr evidence and conclude whether the fault is NETWORK or SERVICE.
Will the manual IP change survive a reboot or new lab session?
No. You add 10.10.10.10/24 directly to the prepared labex0 interface with ip addr, verify it, and remove it in the same lab. Persistent NetworkManager or configuration-file setup is not covered.
Do the download exercises fetch files from the public internet?
No. The wget and curl exercises use a prepared server at localhost:8080, so they focus on command behavior and HTTP responses rather than an external download source.
Why does the final challenge diagnose a service problem?
The exact evidence is a successful ping to 127.0.0.1 and a refused connection to 127.0.0.1:80. The local network path works, but nothing is accepting the requested web connection, so the required conclusion is SERVICE.
