> For the complete documentation index, see [llms.txt](https://cybersecurity-cloud-and-it-notes.gitbook.io/kyles-cybersecurity-cloud-and-it-gitbook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cybersecurity-cloud-and-it-notes.gitbook.io/kyles-cybersecurity-cloud-and-it-gitbook/google-cybersecurity-professional-cert/3.-connect-and-protect-networks-and-network-security/module-1/tcp-ip-model.md).

# TCP IP Model

#### ADHD-Friendly TCP/IP Model Notes! 🚀

**📡 What's TCP/IP Anyway?**

* **TCP/IP** = Transmission Control Protocol / Internet Protocol
* It’s like a rulebook that tells devices how to talk across the internet! 🌍

***

#### 🧩 **Breaking it Down: TCP and IP**

* **TCP** (Transmission Control Protocol):
  * Think of it as two friends calling each other 📞.
  * It connects devices, organizes data, and makes sure the message gets delivered safely.
* **IP** (Internet Protocol):
  * This is the **address system**. 🏠
  * It ensures that when data is sent, it knows where it’s going, just like a GPS! !\[\[Pasted image 20240911194315.png]]

***

#### 📬 **What About Ports?**

* **Ports**:
  * They’re like specific mailboxes 📪 in your apartment (device).
  * Ports help the system know exactly where each bit of data (or "mail") should go.
* **Fun Fact**: Different services use different ports, like:
  * **Port 25** → Email ✉️
  * **Port 443** → Secure web stuff (like HTTPS) 🔒
  * **Port 20** → Big file transfers 📁

***

#### 🏛 **The 4 Layers of the TCP/IP Model:**

This is the blueprint for data travel 🛤️. Security pros use it to spot problems and threats.

1. **Network Access Layer** 🛠️:
   * Deals with hardware and cables (the **physical** stuff).
   * Like how a delivery truck needs roads to get anywhere! 🚚
2. **Internet Layer** 🌍:
   * Where the **IP address** is assigned.
   * Helps data decide whether it stays local or heads to the vast internet!
3. **Transport Layer** 🚦:
   * Controls data traffic.
   * Like a traffic cop 🛑, it directs data flow and checks if everything’s moving smoothly.
4. **Application Layer** 💻:
   * It’s what you, the user, see and interact with.
   * Handles file transfers, emails, and browsing. Like the apps on your phone!

***

#### 🕵️ **Quick TCP/IP Detective Mode:**

* Security pros need to know which layer an attack affects, so they can fix it!
  * **Network Layer** → Hardware problems?
  * **Internet Layer** → Routing/Addressing issue?
  * **Transport Layer** → Data flow issues?
  * **Application Layer** → Service disruption?

***

#### 🌐 **TCP vs OSI: What's the Difference?**

* **TCP/IP**: The 4-layer **roadmap** of how data moves across networks.
* **OSI**: A 7-layer version 📊 that adds more detail. Some layers get smooshed together in TCP/IP. !\[\[Pasted image 20240911194410.png]]

***

#### 🚨 **Key Takeaways:**

* **TCP/IP** helps us see how data is sent and received across the internet.
* It’s a 4-layer model while **OSI** is 7-layered.
* Security pros use this to **troubleshoot** and protect networks.

🎉 **Remember**: It’s like sending letters through the internet post office! 📦