AWS Connecting Private VPCs: How to Establish Secure Network Connections

When it comes to connecting private Virtual Private Clouds (VPCs), there are a few different options depending on your use case and requirements. In this blog, we’ll explore two popular methods for connecting VPCs: VPC peering and VPN connections.

VPC Peering

VPC peering is a way to connect two VPCs within the same AWS region using private IP addresses. When you peer two VPCs, they can communicate with each other as if they were on the same network. This allows resources in both VPCs to access each other directly without having to traverse the public internet.

To set up VPC peering, you’ll need to follow these steps:

1. Identify the VPCs that you want to peer. Each VPC must have a unique CIDR block that does not overlap with the other VPC’s CIDR block.
2. Create a peering connection request in one of the VPCs. This will generate a unique ID for the connection.
3. Accept the peering connection request in the other VPC using the ID generated in step 2.
4. Update the route tables in both VPCs to route traffic to the other VPC’s CIDR block through the peering connection.

Once the peering connection is established and the route tables are updated, you should be able to communicate between the two VPCs using private IP addresses.

One important thing to keep in mind when using VPC peering is that it is limited to connections within the same region. If you need to connect VPCs in different regions, you’ll need to use a different method, such as VPN connections.

Single VPC peering connection

Mutiple VPC peering connections

VPN Connections

VPN connections are a way to securely connect VPCs over the public internet. This allows you to connect VPCs in different regions or even different AWS accounts. VPN connections use encryption to secure the data that is transmitted between the VPCs.

To set up a VPN connection, you’ll need to follow these steps:

1. Set up a virtual private gateway in each VPC. This will act as the VPN endpoint for the VPC.
2. Create a customer gateway. This is the physical device or software that you will use to connect to the virtual private gateway.
3. Create a VPN connection between the virtual private gateway and the customer gateway.
4. Update the route tables in both VPCs to route traffic to the other VPC’s CIDR block through the VPN connection.

Once the VPN connection is established and the route tables are updated, you should be able to communicate between the two VPCs using private IP addresses over the secure VPN connection.

In conclusion, VPC peering and VPN connections are both effective ways to connect private VPCs. VPC peering is great for connecting VPCs within the same region, while VPN connections are better suited for connecting VPCs in different regions or even different AWS accounts. With these two methods, you can easily set up a secure, private network between your VPCs.

Ref: https://docs.aws.amazon.com/vpc/latest/peering/vpc-peering-basics.html