I’m completely new to cloud networking and that is my role in my new position, I have 12+ years traditional Cisco/Brocade/Juniper background. We are moving resources from an EC2-Classic environment to a VPC environment and having a problem creating a reliable connection between the two.
The EC2-Classic and VPC environments both are connected back to an ASA 5520 at a datacenter, those connections are reliable. Then the two environments are also connected together. In the EC2-Classic we are running dual Cohesive VNS3 managers one tunneling to the datacenter, one of them tunnelling to the AWS VPC. It’s the VNS3 tunnel to the VPC that is the problem, the tunnel drops randomly even with traffic generated specifically to keep the tunnel open.
My thought is to spin up an EC2 instance as a Vyatta to create a VPN tunnel from each EC2 instance to itself (using OpenVPN clients) and then tunnel over to the VPC, routing all traffic in that direction; traffic destined to the datacenter would hop through both tunnels. The VNS3 instances would be turned down.
Does anyone have any thoughts on this approach? Are there any known caveats I need to be aware of? Better suggestions or general criticism? 
Any help would be appreciated. References to good EWS documentation would win you my eternal appreciation. I’m not very impressed at the Amazon documents, they dont draw much distinction between the product lines; I spent most of the day browsing and have more questions than when I started.
Thanks in advance,
Per