Devops - Linux Systems and Network Administration

Overview

This course overview presents a practical, example-driven guide to Linux systems and network administration tailored for DevOps and operations teams. It emphasizes command-line diagnostics, reproducible troubleshooting patterns, and safe lab practices so you can move quickly from hypothesis to actionable remediation. The material balances hands‑on tooling with interpretation of results, ethical scanning practices, and clear documentation techniques that support operational handoffs and incident summaries.

What you'll learn

Working through the examples and exercises, you will build a compact toolkit for host discovery, connectivity verification, path and latency diagnosis, and basic service validation from the shell. Core utilities covered include ping and traceroute for reachability and path analysis, telnet-style interactions for simple service checks, whois and DNS lookups for contextual ownership and routing clues, and Nmap for focused service discovery. The emphasis is on reading tool output, forming testable hypotheses, and applying safe practices in production-like environments.

Core topics and instructional focus

Discovery and ethical scanning

Learn pragmatic detection techniques that prioritize operational safety. The course explains when targeted probes are preferable to wide sweeps, how scanning behavior can affect monitoring and alerting systems, and methods for designing experiments that limit collateral impact—using isolated labs, test VLANs, or scheduled windows. Guidance includes responsible documentation, escalation paths, and when to involve security or network teams.

Connectivity testing and path diagnosis

Build repeatable methods for verifying reachability and tracing routing or latency issues in diverse environments. The content contrasts ICMP checks with TCP-level alternatives for networks that filter ping, shows how to interpret traceroute output to isolate problematic hops, and offers heuristics for distinguishing transient disturbances from persistent faults. These patterns help you prioritize fixes and validate remediation steps.

Remote access checks and service validation

Explore lightweight, reproducible interactions to confirm whether services accept connections and behave as expected. Examples demonstrate simple protocol exchanges, banner inspection, and timing observations to reveal handshake issues or misconfigurations. Each example highlights security trade-offs and recommends replacing plain-text checks with secure methods when moving to production.

Context enrichment with lookup tools

Complement on-host probes with external context: DNS resolutions, whois registration data, and provider or hosting mappings. These lookups help you map dependencies, narrow likely points of failure, and prepare clearer inventories or incident reports for stakeholders. Combining local diagnostics with external context improves troubleshooting efficiency and decision making.

Practical guidance, exercises, and projects

Hands-on activities reinforce concepts and encourage safe experimentation. Suggested exercises include building isolated test servers, running controlled scans on a lab subnet, comparing traceroutes under varying conditions, and capturing command outputs for side‑by‑side analysis. The course supplies checklists for protecting production networks, templates for documenting results, and small project ideas—such as a device inventory or a service-behavior report—that translate skills into demonstrable outcomes.

Who should read this

This guide is intended for aspiring and practicing system administrators, DevOps engineers, and network support staff who rely on the command line for day-to-day troubleshooting and monitoring. It’s particularly useful for professionals preparing for operational roles who want concise, tool-focused techniques for diagnostics, inventory work, and initial security posture checks.

How to get the most from the guide

Start with the basic commands and glossary, reproduce examples in an isolated environment, and compare outputs across different network conditions. Keep short notes on observations and hypotheses, convert exercises into small peer-reviewable projects, and practice replacing plain-text examples with secure alternatives to understand operational implications and risks.

Key takeaways

After completing the material you will have a reproducible set of command-line workflows for probing networks responsibly, interpreting diagnostic output to locate issues, and producing concise operational artifacts—such as inventories and incident summaries—that support daily administration and preliminary security assessments.

Suggested next steps

• Recreate example scans in a virtual lab or isolated VLAN and compare results across scenarios.
• Keep a troubleshooting notebook to track recurring patterns and refine hypotheses.
• Share lab findings with peers or community groups to validate techniques and gather feedback.
• Pursue deeper study on secure remote administration, logging impacts, and policies for safe scanning and remediation.