Azure Secure Three-Tier Network

Project Overview

This project demonstrates how to build and secure a three-tier network architecture in Microsoft Azure using Virtual Networks (VNets), Subnets, Network Security Groups (NSGs), Ubuntu Linux Virtual Machines, Apache Web Server, and MySQL.

The objective was to design a secure environment where each application tier communicates only with the required tier while minimizing unnecessary exposure to the public internet.

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Architecture

Architecture Flow

Internet
    │
    ▼
Web VM (Web Subnet)
    │
    ▼
Application VM (App Subnet)
    │
    ▼
Database VM (Database Subnet)

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Azure Services Used

• Azure Virtual Network (VNet)
• Subnets
• Network Security Groups (NSGs)
• Ubuntu Linux Virtual Machines
• Public IP Addresses
• Network Interfaces
• Azure Cloud Shell
• SSH

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Network Design

Tier	Subnet	Purpose
Web	WebSubnet	Hosts the Apache Web Server
Application	AppSubnet	Hosts the Python Application
Database	DatabaseSubnet	Hosts the MySQL Database

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Security Configuration

Web Tier

• Apache Web Server
• Public HTTP access
• SSH restricted to my public IP

Application Tier

• Python HTTP Server running on Port 8080
• Accessible only from the Web subnet
• No direct public access

Database Tier

• MySQL Server
• Port 3306 restricted to the Application subnet
• No Internet access

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Connectivity Tests

The following tests were completed successfully:

• SSH into Web VM
• Web VM → Application VM connectivity
• Application VM → Database VM connectivity
• Python server running on Port 8080
• MySQL installation and service verification
• Network Security Group validation
• Port testing using Netcat (nc)
• ICMP testing using ping

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Project Screenshots

Virtual Machines

Web VM NSG

Application VM NSG

Database VM NSG

Application Server Running

Application Connectivity Test

Database Connectivity Test

Ping Test

MySQL Running

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Skills Demonstrated

• Azure Networking
• Azure Virtual Networks
• Azure Network Security Groups
• Linux Administration
• SSH
• Apache Web Server
• MySQL
• Network Troubleshooting
• Infrastructure Security
• Cloud Infrastructure Documentation

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Repository Structure

Azure-Secure-Three-Tier-Network/
│
├── README.md
├── images/
├── scripts/
│   ├── apache-setup.sh
│   ├── app-server.sh
│   └── mysql-setup.sh

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Key Learning Outcomes

• Designed a secure three-tier Azure network.
• Configured Network Security Groups to control traffic between tiers.
• Deployed and managed Ubuntu virtual machines.
• Tested secure communication between application tiers.
• Practiced Linux administration and network troubleshooting in Azure.

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Author

Agatha Nweze

Azure Cloud Support Engineer | Azure Administrator | Linux | Azure Networking

GitHub: https://github.com/Acnweze