---
title: 'Tutorial: Communicate Between Two VPCs in AWS Using a Single Access Server'
canonical: https://openvpn.net/as-docs/tutorials/tutorial--connect-two-aws-vpcs-with-a-vpc-peering-connection/
product: Access Server Docs
description: Learn how to use Access Server to enable communication between two AWS VPCs with VPC peering, simplifying access to resources in both VPCs without multiple servers.
keywords: VPC peering
---

# Tutorial: Communicate Between Two VPCs in AWS Using a Single Access Server

## Overview

This tutorial will guide you through using a single Access Server to establish seamless communication between two Virtual Private Clouds (VPCs) in AWS, allowing access to resources on both. Instead of deploying multiple Access Servers in each VPC, you can use a single Access Server to connect to both VPCs by creating a VPC peering connection.

By default, communication between two VPCs in AWS is not possible. However, establishing a VPC peering connection and configuring Access Server enables traffic to flow between the two VPCs.

### Key points:

- **Single Access Server:** Use one Access Server to manage connections to both VPCs.
- **VPC peering:** Establish a VPC peering connection to allow communication between two VPCs.
- **No need for multiple servers:** This method eliminates deploying a separate Access Server in each VPC.

By following the steps in this tutorial, you can simplify your network architecture while maintaining secure, centralized access to resources in both VPCs.

> **Note**
>
> In our documentation, we use example IPv4 addresses and subnets [reserved for documentation](https://en.wikipedia.org/wiki/Reserved_IP_addresses#IPv4), such as `192.0.2.0/24`, `198.51.100.0/24`, and `203.0.113.0/24`.
>
> Ensure you replace them with valid IPv4 addresses and subnets for your network(s).

## Prerequisites

Ensure the following resources are set up in AWS:

- **VPC 1:** my-first-vpc (Access Server's VPC)
- **VPC 2:** my-second-vpc (VPC hosting the Ubuntu machine)

Here is an example of the setup:

| **EC2 Instance** | **VPC** | **CIDR** | **Private IP** |
| --- | --- | --- | --- |
| Access Server | my-first-vpc | 192.0.2.0/16 | 192.0.2.54 |
| Ubuntu | my-second-vpc | 198.51.100.0/16 | 198.51.100.188 |

## Step 1: Create the peering connection

1. Sign in to your AWS portal and navigate to **VPC**.
2. Under **Virtual private cloud**, click **Peering connections**.
3. Click **Create peering connection**.
4. Create a name for the peering connection.
5. Select the local VPC to peer with (for this example, **my-first-vpc**).
6. Select the second VPC to peer with (for this example, **my-second-vpc**).
7. Review the information and click **Create peering connection**.
   - A new window shows that the VPC peering connection has been requested, and we need to accept it.
8. Click **Actions**.
9. Click **Accept request**.
10. In the pop-up window, click **Accept request** to finalize the peering connection.

## Step 2: Create the routes

1. Under **Virtual private cloud**, click **Route tables**.
2. Click the **routing table ID** associated with **my-first-vpc** under the **VPC** column.
3. Click **Edit routes**.
4. Add a route to forward the traffic from **my-first-vpc** to **my-second-vpc** through the peering connection. The configuration should look like this:
   - **Destination:** 198.51.100.0/16
   - **Target:** **Peering Connection** and ID (e.g., pcx-123abc)
5. Repeat the steps for **my-second-vpc** to ensure it can route traffic back to **my-first-vpc**:
   - **Destination:** 192.0.2.0/16
   - **Target:** **Peering Connection** and ID (e.g., pcx-123abc)

## Step 3: Allow traffic in Access Server

1. Sign in to your Access Server **Admin Web UI**.
2. Click **Configuration\> VPN Settings**.
3. Set routing to **Yes, using NAT**.
4. Specify the private subnets. Example configuration:
   - 192.0.2.0/16

     198.51.100.0/16

   > **Note**
   >
   > You must use NAT because routing mode is incompatible with VPC peering due to AWS internal restrictions. Consider using a **Transit Gateway** instead of VPC peering if you need routing.
5. Select **Save Settings** and **Update Running Server**.

After completing this step, the Ubuntu machine in **my-second-vpc** should be reachable from a VPN client through the peering connection between the two VPCs.

## Testing connectivity

Once the configuration is complete, you can test connectivity by pinging the Ubuntu machine's private IP from your connected VPN client.

Example:

```
PS C:\Users\Kevin> ping 198.51.100.188

Pinging 198.51.100.188 with 32 bytes of data:
Reply from 198.51.100.188: bytes=32 time=30ms TTL=63
Reply from 198.51.100.188: bytes=32 time=30ms TTL=63
Reply from 198.51.100.188: bytes=32 time=29ms TTL=63
Reply from 198.51.100.188: bytes=32 time=30ms TTL=63
Reply from 198.51.100.188: bytes=32 time=31ms TTL=63

Ping statistics for 198.51.100.188:
    Packets: Sent = 5, Received = 5, Lost = 0 (0% loss)
```

If you encounter any issues or need further assistance, contact our [support team or submit a ticket](https://support.openvpn.com/).

---

Prev: [Tutorial: Extend VPN Connectivity to Amazon AWS VPC Using the AWS VPC VPN Gateway Service](https://openvpn.net/as-docs/tutorials/tutorial--extend-vpn-connectivity-to-amazon-aws-vpc-with-gateway-service.md)
Next: [Tutorial: Using AWS Transit Gateway with Access Server](https://openvpn.net/as-docs/tutorials/tutorial--aws-transit-gateway.md)
Index: https://openvpn.net/as-docs/llms.txt