Add Transit Gateway Routes to VPC Route Tables

Overview of Route Tables

ℹ️ Information: In this section, you will configure the Route Table for each VPC to route traffic through the Transit Gateway.

Naming Convention

Pro Tip: For easier tracking, we use the following naming convention:

• First VPC Main Route Table = Route Table of VPC1
• Second VPC Main Route Table = Route Table of VPC2
• Third VPC Main Route Table = Route Table of VPC3
• Fourth VPC Main Route Table = Route Table of VPC4

Configure Route Table for VPC1

1. Select Route Table
   • Open VPC Management Console
   • Select Route Tables
   • Choose the Route Table of VPC1
   • Click Edit routes

2. Add route
   • Destination: 172.16.0.0/16
   • Target: Select the created Transit Gateway

3. Verify route
   • Confirm the new route has been added
   • This route allows VPC1 to send traffic to the 172.16.x.x network via the Transit Gateway

Configure Route Table for VPC3

1. Add similar route
   • Select the Route Table of VPC3
   • Add a route with Destination 172.16.0.0/16
   • Target = Transit Gateway

2. Verify route
   • Confirm the new route has been added
   • This route allows VPC3 to send traffic to the 172.16.x.x network via the Transit Gateway

Configure Route Tables for VPC2 and VPC4

1. Add route for VPC2
   • Select the Route Table of VPC2
   • Add a route with Destination 0.0.0.0/0
   • Target = Transit Gateway

2. Add route for VPC4
   • Select the Route Table of VPC4
   • Add a route with Destination 0.0.0.0/0
   • Target = Transit Gateway

Connectivity Testing

1. Test Internet connectivity
   • SSH into an EC2 instance in VPC1
   • Try pinging aws.amazon.com to verify Internet access

2. Test inter-VPC connectivity
   • Ping the IP of an EC2 instance in VPC2
   • SSH between instances
   • Test connectivity to VPC3 and VPC4

⚠️ Warning: Make sure to perform all verification steps to confirm connectivity is working correctly.