Module 3: Core Protocols & Network Models

What You’ll Learn

Here we introduce TCP, UDP, Ports, DNS, and the OSI + TCP/IP model.


In this module we will explore the layers of the OSI Model. We will also review the principles of the TCP/IP Model and how TCP/IP functions. We will also cover important network protocols, such as DNS, Telnet, SSH, ICMP, FTP and TFTP.
  • Welcome (8 sec)
    • Get ready to learn about the protocols at the core of networking and the different network models behind modern networking.
TCP, UDP and Ports - 30 minutes
  • Ports (14 min)
    • What are TCP and UDP Ports? We’ve got to understand these before we can truly understand the TCP and UDP protocols themselves.
  • Transmission Control Protocol – TCP (10 min)
    • Good old Transmission Control Protocol!
  • User Datagram Protocol – UDP ( 5 min)
    • And, we must not forget about User Datagram Protocol.
Core Protocols - 31 minutes
  • DNS – The Domain Name System (14 min)
    • Here we will learn about another crucial technology to your everyday web browsing experience – DNS!
  • Diagram of a DNS Request (6 min)
    • And, in this short lesson we will make sure you understand exactly what a DNS Request is.
  • Core protocols (11 min)
    • There’s a few protocols that we need to make sure you completely understand. Let’s get down with some Telnet, SSH, ICMP, FTP and TFTP!
Networking Models - 51 minutes
  • The OSI Model – Intro to OSI and the 7 Layers (12 min)
    • We’ll begin breaking down the OSI model by learning about the 7 layers.
  • The OSI Model – Passing Through the Layers (5 min)
    • Now that we know what the 7 layers are we can see how data looks as it moves through each layer of the OSI model.
  • The OSI Model – Devices and Protocols in OSI (16 min)
    • In this lesson, we will look at the OSI model from the perspective of different network devices and the layers at which they function.
  • The OSI Model – Remembering the Layers (4 min)
    • We’ll wrap up the lessons on the OSI model with some ways to remember the layers from bottom to top and top to bottom.
  • The TCP/IP Model (14 min)
    • Now that we understand OSI we can quickly deconstruct the TCP/IP Model.


Guidance and Motivation


The program is created by engineering veterans who worked at Cisco, Arista Networks, top VARs, and in the U.S. Air Force. The founders have trained over 1000+ engineers for the military and built this curriculum from the ground up in order to make you job and mission-ready!

Over 40+ years of combined industry experience have been poured out into our Cyber Security Specialist program to take anyone from Zero to Engineer in 14 to 24 weeks.

Terry Kim

Founder and CEO of NexGenT – I’ve worked in the IT industry for 15+ years before starting this company and have been fortunate enough to work for some amazing companies such as Cisco Systems, Arista Networks, and Dimension Data as a Network Architect/Systems Engineer. And my mission is to help you level up in Information Technology!

Jacob Hess

I’m a Network Engineer, Entrepreneur, and Air Force veteran who is passionate about computer networking, education, and high performance teams. I enjoy people, teaching, learning, business, and cutting edge technology.

Pat Gorman

Pat Gorman, is a lover of all things tech-related & learning something new every day is his motive. Pat is a huge sports guy and plays soccer and hockey weekly. He enjoys teaching and spreading cybersecurity and other IT knowledge to the world. He holds quite a few IT certifications under his belt