Create Transit Gateway Attachments

Overview of Transit Gateway Attachments

ℹ️ Information: In this section, you will configure Transit Gateway Attachments to connect your VPCs to the previously created Transit Gateway.

Transit Gateway Attachments Architecture

Steps to Create Transit Gateway Attachments

  1. Access VPC Management Console
    • Open VPC Management Console
    • Select Transit Gateway Attachments
    • Click Create Transit Gateway Attachment

Create Transit Gateway Attachment

  1. Basic Configuration
    • Name tag: Enter Transit Gateway Attachment 1
    • Transit Gateway ID: Select the ID of the Transit Gateway you created
    • Attachment type: Select VPC

Basic Configuration

  1. Detailed Configuration
    • VPC ID: Select First VPC (VPC1)
    • Subnet IDs: Select the subnets in the corresponding Availability Zones
    • Tags: Create a new tag with value Transit Gateway Attachment 1
    • Click Create transit gateway attachment

Detailed Configuration

  1. Confirm Successful Creation
    • Wait until the status changes to Available

Creation Confirmation

  1. Create Attachment for VPC2
    • Repeat the steps above for VPC2
    • Use an appropriate name (e.g., VPC2)

Create Attachment VPC2 Create Attachment VPC2 Create Attachment VPC2

  1. Create Attachment for VPC3
    • Repeat the process for VPC3
    • Use an appropriate name (e.g., VPC3)

Create Attachment VPC3 Create Attachment VPC3

  1. Create Attachment for VPC4
    • Complete the process for VPC4
    • Use an appropriate name (e.g., VPC4)

Create Attachment VPC4 Create Attachment VPC4

💡 Pro Tip: In a production environment, you should attach all subnets of each VPC to the Transit Gateway to ensure high availability.

Attachments Overview

Connectivity Testing

  1. SSH into an EC2 instance in VPC1
    • Use the command: ping <Public IPv4 of EC2> -c5 to ping the Third EC2 host

Connectivity Test

  1. Test connectivity between VPCs
    • Try pinging the private IP addresses of instances in other VPCs
    • Note: Connectivity will fail because routing has not been configured yet

Inter-VPC Connectivity Test

⚠️ Warning: Connectivity will fail because:

  • Default route table association was disabled
  • Default route table propagation was disabled
  • Routing configuration is required in the next steps