Amazon VPC provides the flexibility to combine the AWS managed VPN and software VPN options to connect multiple VPCs. With this design, you can create secure VPN tunnels between a software VPN appliance and a virtual private gateway, allowing instances in each VPC to seamlessly connect to each other using private IP addresses. This option uses a virtual private gateway in one Amazon VPC and a combination of an internet gateway and software VPN appliance in another Amazon VPC, as shown in the following figure.

Note that this design introduces a potential single point of failure into the network design. For additional information, see Appendix A: High-Level HA architecture for software VPN instances.