Create VPC for VPN

Setting Up VPC for Site-to-Site VPN

ℹ️ Overview

  • In this section, we will create a new VPC to simulate a Branch Office network.
  • The VPC will be configured with the CIDR block 10.11.0.0/16.
  • It will include a public subnet and an Internet Gateway for internet connectivity.

⚠️ Prerequisites

  • Access to the AWS Console with sufficient permissions to create VPC resources.
  • Basic understanding of CIDR and subnet planning.

Create VPC and Subnet

  1. Access the VPC Dashboard
    • Select Your VPCs
    • Click Create VPC

Create VPC

  1. Configure the new VPC

    • Resource type: Select VPC only
    • Name: Enter ASG VPN
    • IPv4 CIDR: Enter 10.11.0.0/16
    • Click Create VPC

    💡 CIDR Planning: This VPC uses 10.11.0.0/16 to simulate an on-premises network, different from the main VPC (10.10.0.0/16) to avoid IP conflicts.

Create VPC

Create VPC

  1. Create a Public Subnet
    • Go to Subnets
    • Click Create subnet
    • Choose the VPC ASG VPN

Create VPC Create VPC

  1. Configure the Subnet
    • Name: Enter VPN Public
    • Availability Zone: Select ap-southeast-1b
    • IPv4 CIDR: Enter 10.11.1.0/24
    • Click Create subnet

Create VPC Create VPC

Configure Internet Connectivity

  1. Enable Auto-assign Public IP

    • Select the VPN Public subnet
    • Click Actions > Edit subnet settings
    • Enable Auto-assign public IPv4 address
    • Click Save

    ⚠️ Important: The Customer Gateway EC2 instance needs a public IP to establish VPN tunnels with AWS.

Create VPC Create VPC Create VPC

  1. Create an Internet Gateway
    • Go to Internet Gateways
    • Click Create internet gateway
    • Name: Enter Internet Gateway VPN
    • Click Create

Create VPC Create VPC

  1. Attach the Internet Gateway to the VPC
    • Select the newly created IGW
    • Click Actions > Attach to VPC
    • Choose the VPC ASG VPN
    • Click Attach

Create VPC Create VPC Create VPC

Configure Route Table

  1. Create a new Route Table
    • Navigate to Route Tables
    • Click Create route table
    • Name: Enter Route table VPN - Public
    • VPC: Select ASG VPN
    • Click Create

Create VPC Create VPC

  1. Add Route for Internet Access
    • Open the Routes tab
    • Click Edit routes
    • Click Add route
    • Destination: Enter 0.0.0.0/0
    • Target: Select the Internet Gateway VPN
    • Click Save changes

Create VPC Create VPC

  1. Associate the Subnet
    • Go to the Subnet associations tab
    • Click Edit subnet associations
    • Select VPN Public subnet
    • Click Save associations

Create VPC Create VPC

🏗️ Architecture Summary

VPC ASG VPN (10.11.0.0/16) - Simulates On-Premises Network
├── VPN Public Subnet (10.11.1.0/24)
│   └── Will host Customer Gateway EC2
├── Internet Gateway VPN
│   └── Provides internet access for VPN tunnels
└── Route Table VPN - Public
    └── Routes 0.0.0.0/0 → Internet Gateway

💡 Pro Tips

  • This VPC simulates an on-premises data center or branch office
  • The Customer Gateway EC2 will act as the VPN endpoint
  • Ensure CIDR blocks don’t overlap with your main VPC (10.10.0.0/16)
  • Use descriptive names with “VPN” prefix for easy identification

✅ Completed: VPN VPC infrastructure is ready for Customer Gateway deployment!