> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ahmadraza.in/llms.txt
> Use this file to discover all available pages before exploring further.

# CustomVnet

# Azure  VPC/Vnet Setup Guide for Public and Private Subnets

This document provides a step-by-step guide for replicating an AWS VPC infrastructure in Azure, with an equivalent setup for **subnets**, **route tables**, **Internet Gateway**, **NAT Gateway**, and **Network Security Groups (NSGs)**.

## 1. Create a Virtual Network (VNet)

In AWS, a **VPC** is equivalent to a **VNet** in Azure. This is the first step to replicate your AWS infrastructure.

### Steps:

1. **Create a new Virtual Network**:
   * **Resource Group**: Create or select an existing resource group.
   * **Name**: `prod-vnet`
   * **Region**: **Central India** (or another region closest to Mumbai)
   * **Address space**: Use the same CIDR range as your VPC, e.g., `10.0.0.0/16`.

2. **Add Subnets**:
   * **Public subnets**:
     * **Subnet-1 (prod-public-subnet-1)**: `10.0.0.0/20`
     * **Subnet-2 (prod-public-subnet-2)**: `10.0.16.0/20`
     * **Subnet-3 (prod-public-subnet-3)**: `10.0.32.0/20`
   * **Private subnets**:
     * **Subnet-1 (prod-private-subnet-1)**: `10.0.48.0/20`
     * **Subnet-2 (prod-private-subnet-2)**: `10.0.64.0/20`
     * **Subnet-3 (prod-private-subnet-3)**: `10.0.80.0/20`

3. Click **Create**.

## 2. Create and Assign Route Tables

### Steps:

1. **Create two Route Tables**:
   * **prod-public-route-table**
   * **prod-private-route-table**

2. For **prod-public-route-table**:
   * **Route**: `0.0.0.0/0` → **Internet Gateway**

3. For **prod-private-route-table**:
   * **Route**: `0.0.0.0/0` → **Virtual Network Gateway** (for NAT Gateway)

4. **Associate Route Tables** with Subnets:
   * **Public subnets**: Associate with **prod-public-route-table**
   * **Private subnets**: Associate with **prod-private-route-table**

## 3. Set Up Internet Gateway (Public IP)

Azure uses a **Public IP Address** and **Load Balancer** for public-facing resources.

### Steps:

1. **Create a Public IP Address** for the **Internet Gateway**.
2. Assign the public IP to a **Load Balancer** or **VM** for internet-facing resources.

## 4. Set Up NAT Gateway

### Steps:

1. Go to **NAT Gateway** in Azure.
2. **Create a NAT Gateway**:
   * Assign a public IP.
   * Associate the NAT Gateway with the **private subnets**.

## 5. Set Up Network Security Groups (NSGs)

### Steps:

1. **Create NSGs**:
   * **Public NSG**: Allow inbound internet traffic.
   * **Private NSG**: Allow traffic only from within the VNet or specific subnets.

2. **Assign NSGs** to respective subnets:
   * Public subnets: Assign the **Public NSG**.
   * Private subnets: Assign the **Private NSG**.

## 6. Deploy Resources

* **Validate your network setup** by deploying **VMs** in the following manner:
  * **VM in Public Subnet**: Test internet connectivity.
  * **VM in Private Subnet**: Verify traffic flow through the NAT Gateway.

## 7. Monitoring and Automation

* Use **Azure Monitor** for logging and monitoring traffic.
* Add alerts for traffic anomalies or misconfigurations.
* For repeated setups, use **Azure CLI**, **PowerShell**, or **Terraform** for automation.

## Architecture Diagram

```plaintext theme={null}
               +------------------------------------+
               |             Azure VNet            |
               +------------------------------------+
               |  Address Space: 10.0.0.0/16        |
               +------------------------------------+
                 /         |          |          \
                /          |          |           \
        +------------+ +------------+ +------------+ +------------+
        | Public Subnet| | Public Subnet| | Public Subnet| | Private Subnet|
        | 10.0.0.0/20  | | 10.0.16.0/20| | 10.0.32.0/20| | 10.0.48.0/20  |
        +------------+ +------------+ +------------+ +------------+
                 |          |            |           | 
         +-----------------------------------------------+
         |                 NAT Gateway                  |
         +-----------------------------------------------+
                 |          |            |           |
        +-----------------+ +------------------+ +-----------------+
        | Private Subnet  | | Private Subnet    | | Private Subnet  |
        | 10.0.64.0/20    | | 10.0.80.0/20      | | 10.0.96.0/20    |
        +-----------------+ +------------------+ +-----------------+
```

> This diagram represents your **VNet**, subnets (both public and private), and **NAT Gateway** setup in Azure.