This post is part of my ongoing TryHackMe journey. I’m documenting each room to reinforce what I’ve learned, along with additional research and explanations that helped me better understand the concepts.
Date Completed: 8/8/2025
Difficulty: Easy
Overview
This room went over basic networking concepts and tools.
Key Concepts
Encapsulation
OSI Model
TCP/IP Model
Network Commands
Notes
OSI Model contains 7 layers and is an easier model to demonstrate and understand how data moves through the network
TCP/IP Model contains 4 layers and covers the same functions as the OSI Model but is based on real-world internet protocols
Encapsulation is the process of adding unique data packaging as data moves down the layers. Each layer adds its own package of information, such as headers and/or trailers, to prepare it for transmission.
De-encapsulation is the reverse process where each layer removes the package information as data moves up the layers. This process prepares the data to be received and used by the application.
OSI Model | TCP/IP Model | Mnemonic to help memorize OSI Model |
|---|---|---|
Layer 1: Physical | Network Interface | Please |
Layer 2: Data Link | Do | |
Layer 3: Network | Internet | Not |
Layer 4: Transport | Transport | Throw |
Layer 5: Session | Sausage | |
Layer 6: Presentation | Application | Pizzas |
Layer 7: Application | Away |
Network Commands | Description | Example | Why is this handy? |
|---|---|---|---|
Ping | Tests whether the target is reachable and measures how long it takes to send and receive a response from the target | ping examplesite.com |
|
Traceroute (Linux/macOS) Tracert (Windows) | Maps which server the packet goes through (known as a "hop") and how long each hop takes to respond | traceroute examplesite.com |
|
Whois | Retrieves the domain's registration information | whois examplesite.com |
|
Dig | Finds recursive DNS servers of user's choice for info about domains | dig examplesite.com @ 1.2.3.4 |
|
Acronyms
TTL: Time To Live
Measures in milliseconds how long the record is stored in DNS cache
TLD: Top Level Domain
The extensions such as .com, .org, .net
TLD Servers are servers grouped by extension. Each server contains information that tells which authoritative name server is responsible for each domain under that extension
DIG: Domain Information Groper
Command tool to find DNS servers and retrieve domain information
