Cable problems can often look like application issues, but they require a different kind of troubleshooting. In this episode, we review cable specifications like length limits, signal loss, impedance, and interference resistance. You'll learn how to recognize mismatches between cable category and intended use, such as trying to run 10 Gbps over Cat 5e or exceeding fiber distance ratings.

We also touch on specialized cable applications, including shielded twisted pair (STP) in noisy environments, coaxial for certain legacy links, and fiber for long-distance high-throughput needs. Choosing the wrong cable—or installing it improperly—can introduce latency, data corruption, or complete signal failure. This episode prepares you to spot cable-related issues before they turn into costly downtime.

Once you’ve confirmed the cause of a network issue, it's time to solve it. This episode covers the final stages of the troubleshooting methodology: establishing a plan of action, implementing the solution, verifying functionality, and documenting everything. You’ll learn how to evaluate risk before making changes, how to plan rollback strategies, and how to confirm that your fix didn’t break something else.

We also explain why documentation is critical—not just for compliance, but for future troubleshooting, audits, and team communication. From updating diagrams to entering notes in a ticketing system, proper documentation closes the loop and helps the next technician pick up where you left off. This episode reinforces the professional mindset of fixing problems responsibly and transparently.

The foundation of effective troubleshooting is a structured approach. In this episode, we introduce the CompTIA troubleshooting methodology, focusing on the first few steps: identifying the problem, establishing a theory of probable cause, and testing that theory. You'll learn how to ask the right questions, collect information from logs and users, and avoid jumping to conclusions. Proper problem identification prevents wasted time and unnecessary fixes.

We also explore how to classify symptoms, consider recent changes, and determine if a problem is user-specific or system-wide. By the end of the episode, you’ll be able to confidently break down a vague complaint like “the network is slow” into actionable clues that guide your next steps. This episode is about starting smart—because the right first move saves hours of guesswork.

In this final domain, we turn our focus to troubleshooting—a skill that ties together everything you’ve learned so far. This episode introduces Domain 5 and outlines the key areas it covers, including troubleshooting methodology, cable testing, routing diagnostics, wireless issues, and performance analysis. Unlike previous domains that focused on setup and design, this one is about identifying and fixing what’s already built. If Domain 2 was implementation and Domain 3 was operation, this domain is where the rubber meets the road.

You’ll also be introduced to common tools, processes, and structured methods that help you logically step through a network issue. The goal is not just to guess the fix, but to isolate the problem, test assumptions, and document your actions. This is the real-world part of networking—where things go wrong and you make them right.

Security tools can’t catch every threat—but informed users often can. This episode looks at the balance between technical detection methods and user-driven prevention. We start by examining detection tools like antivirus, IDS/IPS, SIEM platforms, and anomaly-based monitoring. You’ll learn how these systems generate alerts, how tuning reduces false positives, and how incident escalation paths are defined.

We then turn to user training: simulated phishing campaigns, password best practices, and regular awareness sessions. Employees are the first line of defense in many attacks, and effective training programs reduce click-through rates, credential leaks, and shadow IT risk. This episode ties together human and technical defenses for a more resilient organization.

While cyber defenses are critical, physical security is just as important. In this episode, we explain how physical access controls protect infrastructure from unauthorized tampering, theft, or sabotage. You’ll learn about badge systems, biometrics, mantraps, camera placement, and hardware locks. These controls help restrict access to wiring closets, server rooms, and device enclosures.

We also cover secure asset disposal practices such as drive wiping, degaussing, shredding, and certificate documentation. Disposing of equipment improperly can lead to data leakage and compliance violations. This episode reinforces the idea that network security must include the physical realm—from building entry to hardware end-of-life procedures.

Wireless networks require layered security controls to keep unauthorized users out and ensure a clean client experience. In this episode, we cover advanced wireless protections including MAC filtering, client isolation, and captive portals. MAC filtering adds a basic layer of access control by allowing or denying clients based on their hardware addresses, though it must be combined with other controls for true security.

We also discuss client isolation, which prevents wireless clients on the same SSID from communicating with each other—a useful feature in public or guest networks. Finally, we explain captive portals and how they enforce policy acceptance, credential entry, or billing before granting full internet access. These tools are common in enterprise, hospitality, and campus deployments, and understanding them helps secure wireless deployments with more than just a password.

Firewalls and access control lists are the gatekeepers of your network, and understanding how to configure them correctly is essential. This episode explains how to structure firewall rules and ACLs (Access Control Lists) using principles like implicit deny, least privilege, and rule order. You'll learn how rules are evaluated top-down and why a misplaced permit or deny can either expose sensitive systems or unintentionally block legitimate traffic.

We cover standard vs. extended ACLs, how to apply them to inbound vs. outbound traffic, and best practices like logging, naming, and change documentation. Troubleshooting ACL behavior is also discussed, with a focus on rule testing and log interpretation. This episode equips you with the skills to both lock down traffic and troubleshoot configuration issues with confidence.

Securing the network starts with securing its devices. In this episode, we focus on hardening best practices for routers, switches, and firewalls. This includes disabling unused interfaces, enforcing strong password policies, and limiting access with ACLs and administrative timeouts. We also explore remote access security—ensuring SSH replaces Telnet, enabling HTTPS instead of HTTP, and monitoring logins for anomalies.

Firmware and software vulnerabilities are common attack vectors, so we also discuss version control, patch scheduling, and rollback planning. You’ll learn how to establish a secure configuration baseline and maintain it through automated compliance checks. This episode is essential for keeping infrastructure components secure and aligned with organizational policies.

Advanced network protection mechanisms focus on securing internal traffic and device behavior. This episode introduces three such features: Dynamic ARP Inspection (DAI), DHCP Snooping, and Control Plane Policing (CoPP). DAI helps detect and block ARP spoofing attempts by validating ARP packets against known trusted entries. This is especially important in VLAN-segmented environments where one compromised host can poison entire segments.

Next, we cover DHCP Snooping, which prevents rogue DHCP servers from assigning false IP configurations by limiting DHCP responses to trusted ports. Lastly, we explain CoPP—a method of rate-limiting traffic directed at the control plane to protect CPUs from overload during attacks. Together, these technologies form a powerful triad of internal protection. This episode helps you move beyond basic firewalling and into granular switch and router defenses.