What is an AWS Transit Gateway?
- An AWS Transit Gateway is a virtual router that allows you to connect multiple VPCs and on-premises networks together, simplifying network architecture and reducing operational overhead.
- It acts as a central hub for all your network traffic, making it easier to manage and scale your network.
- It use hub and spoke technology i.e., Transit Gateway act as a Hub and the VPC acts as a Spoke
When to Use
You should consider using an AWS Transit Gateway in the following scenarios:
- Complex Network Architectures: If you have a large number of VPCs and on-premises networks that need to communicate with each other, a Transit Gateway can simplify your network design.
- Hybrid Cloud Environments: If you have a hybrid cloud environment with both on-premises and cloud resources, a Transit Gateway can help you connect them seamlessly.
- Multi-Region Deployments: If you have resources deployed across multiple AWS Regions, a Transit Gateway can help you connect them together and route traffic efficiently.
- High-Performance Networking: Transit Gateways can provide high-performance networking capabilities, including low latency and high throughput.
Use Cases
- Connecting Multiple VPCs: You can connect multiple VPCs together, regardless of their Availability Zones or Regions.
- Connecting On-Premises Networks: You can connect your on-premises networks to your VPCs using VPN connections or AWS Direct Connect.
- Creating Hub-and-Spoke Topologies: You can create hub-and-spoke topologies, where a central Transit Gateway acts as the hub and your VPCs and on-premises networks are the spokes.
- Implementing Network Segmentation: You can use route tables and route filters to segment your network traffic and enforce security policies.
Data Transfer Charges
Data transfer charges for Transit Gateway are based on the amount of data transferred between VPCs and on-premises networks. AWS charges for data transfer between VPCs and on-premises networks, as well as data transfer to and from the internet.
Pricing Comparison
The cost of using a Transit Gateway depends on the number of attachments, the amount of data transferred, and the specific configuration of your network. AWS provides a pricing calculator to help you estimate the cost of your Transit Gateway deployment.
Advantages of AWS Transit Gateway
- Simplified Network Architecture: Reduces the complexity of managing multiple VPCs and on-premises networks.
- Improved Network Performance: Provides high-performance networking capabilities, including low latency and high throughput.
- Enhanced Security: Allows you to implement granular security policies to protect your network.
- Scalability: Easily scale your network by adding or removing VPCs and on-premises networks.
- Centralized Management: Provides a centralized point of control for your network.
Disadvantages of AWS Transit Gateway
- Complexity: Can be complex to configure and manage, especially for large and complex networks.
- Cost: Can be expensive, especially for large-scale deployments.
Implementation
Step 1: Go to Transit Gateway Dashboard and click on create Transit Gateway button.
Step 2: Specify the following details -
- Name
- Description
- Autonomus System Number/ASN (must be between 64512-65534)
- Enable multicast support for multicast traffic
Step 3: Click on Create transit Gateway
Create Transit Gateway Attachment
Step 4: Go to VPC ➡️ Transit Gateway ➡️ Transit Gateway Attachment. click on Create Transit Gateway Attachment
Step 5: Enter the following details -
- Name
- TGW Gateway ID (the one we created above)
- Attachment Type (Select VPC)
- Configure it according to your need
- Select VPC for which you to associate
Step 6: Click on Create Attachment
(Create for one more VPC)
Configure the VPC route table
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Points to remember
- TGW has it's own Routing table that has route to that VPC from the TGW
- VPC Transit Gateway name always start with
tgw-XXXXXXX - There's no explicit limit on the number of Transit Gateways you can create in a single AWS account.