Exploring Network Operations and Security in Depth

In the latest phase of my retraining to become an IT specialist in system integration, we are diving into a much more exciting and relevant topic: "Ensuring the Operation and Security of Networked Systems". After a few slower and more theoretical learning modules, this unit feels like a breath of fresh air—practical, technical, and deeply connected to my personal interest in cybersecurity. It’s a subject that offers both depth and real-world application, and I’m eager to share what I’m currently exploring and learning.

Core Concepts and Network Fundamentals

The first part of the module revisits core networking concepts, helping to reinforce and deepen our understanding of the fundamentals. These basics are essential not only for administration tasks but also for recognizing potential security gaps.

We’re currently working through:

• The OSI Model – Layer by layer, we are analyzing how communication flows through systems and how each layer can be monitored or attacked.
• Transport Protocols (TCP/UDP) – Understanding how data is reliably or unreliably sent and how that affects latency, packet loss, and vulnerability to exploits.
• Ports and Protocols – Knowing which services typically use which ports and how to spot unusual activity.
• Routing, IPv4 and IPv6 – A detailed dive into how packets find their way across networks, including static and dynamic routing, and a comparison of IP addressing schemes.
• Subnetting – This includes both IPv4 and IPv6, which is especially helpful for segmenting networks and planning address space in more complex topologies.
• Address Ranges and Multicast – We’re learning how broadcast and multicast traffic function, particularly under IPv6, and what implications this has for security and performance.
• ICMPv6 and IP Header Structures – Understanding packet anatomy and how headers differ between IPv4 and IPv6 is critical for monitoring and filtering traffic.

All of these areas are being reinforced with hands-on labs and examples, which helps connect the theoretical with the practical. I personally appreciate this blended approach—it allows me to apply what I’ve already started learning through my own experiments with Wireshark and virtual labs.

Encryption and Secure Communication

Another essential section focuses on encryption methods and protocols. We're learning how data can be protected during transmission and the difference between symmetric and asymmetric encryption.

So far, the following concepts are on the schedule:

• Symmetric vs. Asymmetric Encryption – Including practical examples of where each is used.
• PGP (Pretty Good Privacy) – Introduction to encrypted email and document security.
• SSH (Secure Shell) – Already familiar from my own server work, but now we’re diving deeper into key-based authentication and session hardening.
• TLS (Transport Layer Security) and IPSec – Key protocols that secure HTTPS and VPNs, respectively.

This part is particularly exciting for me, because encryption is a pillar of modern cybersecurity. The more I understand the inner workings, the more I can apply this knowledge when performing traffic analysis or setting up hardened services.

Practical Linux Labs

The first week of this module also includes practical exercises on Linux systems. We’re going to install and configure a web server, most likely Apache or Nginx, under Linux. While I already have some experience setting up servers (especially for my own Ghost blog on a Raspberry Pi), doing this from scratch in a classroom environment adds depth to my skillset.

We’ll cover:

• Linux web server installation and configuration
• User and permission management
• Service monitoring and log analysis

This will all serve as preparation for the second week, where the focus will shift even more toward real-world security.

What’s Coming Next: Cybersecurity and Penetration Testing

The second week is shaping up to be the most exciting yet. It marks the beginning of a deeper look into cybersecurity, a field that directly aligns with my long-term goal of becoming a Red Teamer in offensive security.

Some of the upcoming topics include:

• StGB §202 (Hacker Paragraph) – Understanding the legal implications of penetration testing and what separates ethical hacking from criminal activity.
• Introduction to Penetration Testing – Covering the process of reconnaissance, scanning, exploitation, and reporting.
• Tools and Techniques – We'll be introduced to tools like Nmap, Wireshark, and others. As someone who already works through platforms like TryHackMe, I’m very eager to see how these tools are applied in a formal training environment.
• Wireshark – A deeper dive into packet analysis. We'll cover:
  • Capturing network traffic
  • Using capture and display filters
  • Analyzing protocols like ARP, TCP, UDP, DNS
  • Monitoring unencrypted protocols like HTTP and FTP
  • Exploring encrypted protocols like SSH, SFTP, TLS

Being able to monitor and interpret live traffic is one of the most powerful skills in network security, and practicing this hands-on in class is an invaluable opportunity.

• Firewall Concepts – We’ll explore different firewall types and packet filters, something I’ve touched on in my personal lab but am excited to explore more deeply.
• Intrusion Detection & Prevention (IDS/IPS) – This includes setting up and using tools like Snort, and understanding how to recognize patterns of attack.
• IT Risk Analysis – Group work will focus on assessing threats, evaluating impact, and defining countermeasures. It’s great to see a structured approach to something that is often quite abstract.

Looking Ahead

This module has already sparked new motivation in me. After some of the more monotonous units, finally having a subject that blends networking, Linux, and security feels like I’m moving forward again. It’s a chance not only to learn but to apply what I’ve already been doing in my personal time in a professional and structured way.

I’m particularly excited for the penetration testing introduction. It’s not only aligned with my passion for cybersecurity, but also reinforces the value of the learning path I’ve chosen with platforms like TryHackMe, my Ghost blog documenting my journey, and the projects I’ve been working on independently.

There’s a lot more to come, and I’m looking forward to sharing what I learn over the next weeks. The combination of legal, theoretical, and practical security work makes this one of the most valuable phases of my retraining so far.