Three-Tier Network Architecture Using Cisco Packet Tracer

Overview

This project demonstrates the implementation of a Three-Tier Network Architecture using Cisco Packet Tracer 9.0.

The topology follows a standard enterprise network design consisting of the Core Layer, Distribution Layer, Access Layer, and End Devices.

The project demonstrates end-to-end communication using ICMP (Ping) and packet analysis through Simulation Mode.

This project is intended for networking students, beginners, and networking enthusiasts who want to understand enterprise network architecture through hands-on simulation.

Network Topology

Three-Tier Network Architecture

The following topology demonstrates communication between two end devices through the Core, Distribution, and Access layers.

Three-Tier Architecture

Layer	Purpose	Devices Used
Core Layer	High-speed backbone that interconnects distribution switches.	Cisco Catalyst 3560-24PS
Distribution Layer	Aggregates access switches and performs routing, filtering, and policy enforcement.	Cisco Catalyst 3560-24PS
Access Layer	Connects end devices to the enterprise network.	Cisco Catalyst 2960
End Devices	User devices connected to the network.	PCs

Objectives

• Understand the Three-Tier Enterprise Network Architecture.
• Design an enterprise topology using Cisco Packet Tracer.
• Configure Cisco 3560 and Cisco 2960 switches.
• Configure IP addresses on end devices.
• Verify network connectivity using ICMP Ping.
• Analyze packet flow using Simulation Mode.
• Observe ICMP packet transmission through the network layers.
• Understand the role of each network layer.

Features

• Enterprise Three-Tier Network Design
• Core, Distribution, and Access Layers
• Cisco Catalyst 3560 & 2960 Switches
• IP Address Configuration
• ICMP Connectivity Verification
• Simulation Mode Packet Analysis
• ICMP Packet Analysis
• ICMP Echo Request and Echo Reply
• Clean and Layered Network Topology

IP Addressing

Addressing Table

Device	Interface	IP Address	Subnet Mask
PC0	FastEthernet0	192.168.1.10	255.255.255.0
PC1	FastEthernet0	192.168.1.20	255.255.255.0

Required Resources

Hardware

• Personal Computer

Software

• Cisco Packet Tracer 9.0
• Windows 10 / Windows 11

Network Devices

• 1 × Cisco Catalyst 3560 Core Switch
• 2 × Cisco Catalyst 3560 Distribution Switches
• 2 × Cisco Catalyst 2960 Access Switches
• 2 × PCs
• Copper Straight-Through Cables

Procedure

Step 1 – Create the Network Topology

Add the following devices:

• Core Switch (3560-24PS)
• Distribution Switch-1 (3560-24PS)
• Distribution Switch-2 (3560-24PS)
• Access Switch-1 (2960)
• Access Switch-2 (2960)
• PC0
• PC1

Step 2 – Connect the Devices

Use Copper Straight-Through cables.

            Core Switch
            /         \
 Distribution1     Distribution2
       |                 |
 Access Switch1     Access Switch2
       |                 |
      PC0               PC1

Step 3 – Configure IP Addresses

Configure the following IP addresses.

Device	IP Address
PC0	192.168.1.10
PC1	192.168.1.20

Step 4 – Verify Connectivity

Open Command Prompt on PC0.

Run

ping 192.168.1.20

Successful replies confirm network connectivity.

Step 5 – Analyze in Simulation Mode

Switch Cisco Packet Tracer to Simulation Mode.

For this demonstration, the Event List is filtered to ICMP.

Use:

• Add Simple PDU
• Capture / Forward
• Auto Capture / Play

Network Communication Path

PC0
 ↓
Access Layer
 ↓
Distribution Layer
 ↓
Core Layer
 ↓
Distribution Layer
 ↓
Access Layer
 ↓
PC1

Simulation Demonstration

The following GIF demonstrates ICMP packet transmission through the Three-Tier Network Architecture using Cisco Packet Tracer Simulation Mode.

Simulation Features

• Event List
• ICMP Protocol Filtering
• OSI Layer Inspection
• Packet Animation
• Capture / Forward
• Auto Capture / Play
• ICMP Echo Request
• ICMP Echo Reply

Expected Output

• ✅ Successful Ping
• ✅ ICMP Echo Request
• ✅ ICMP Echo Reply
• ✅ Packet Traverses the Core Layer
• ✅ Packet Traverses the Distribution Layer
• ✅ Packet Traverses the Access Layer
• ✅ Successful End-to-End Communication

Observation

Layer	Function
Core Layer	High-speed backbone connectivity
Distribution Layer	Routing, filtering, policy enforcement
Access Layer	Connects end devices
End Devices	Source and destination hosts

Result

The Three-Tier Network Architecture was successfully designed, configured, and tested using Cisco Packet Tracer 9.0.

The simulation demonstrated how packets travel through the Core, Distribution, and Access layers of an enterprise network. End-to-end connectivity between PCs was verified using ICMP Ping.

Cisco Packet Tracer Simulation Mode was used to analyze ICMP packet transmission through the Core, Distribution, and Access layers, providing a practical understanding of packet flow within a hierarchical enterprise network.

📂 Download Project Files & Source Code

I have shared the complete Cisco Packet Tracer (.pkt) project, network topology, and related files on my GitHub repository.

🔗 GitHub Repository: Demonstration-of-Three-Tier-Network-Architecture

Feel free to download the project, explore the configuration, and use it for learning or academic purposes.

If you found this tutorial helpful, please consider:

- ⭐ Starring the GitHub repository
- 🍴 Forking the project
- 💬 Sharing your feedback or suggestions
- 👨‍💻 Following me on GitHub for more Cisco Packet Tracer labs, networking tutorials, and open-source projects.

Thank you for reading, and happy learning!