Amazon VPC – Can a Normal VPN Connection Be Used?

Are the services you're accessing Web Services, or something else?

If they are web services, then what you've described in your non-ideal setup would work quite well. You would set up a 3rd server that would act as a proxy for your web services, accepting requests from your "cloud" server, and tunneling them over the VPN to the corporate network (This is called a "reverse proxy").

Slapping on SSL (even self-signed would do as you only have to trust yourself) and only permitting the IP address of your "cloud" server through the firewall would even keep it pretty secure, but you're right in that its a lot of additional management overhead (although I've done similar things myself in the past, and once they're running you can usually just leave them alone for years at a time).

What I would suggest is finding a "cloud" provider (I use the term loosly, as a "cloud" server is really just a VPS bundled with a few other external technologies) where you have full administrator/root access to the machine and then create a VPN the way you would normally.

This will probably cost a small amount than other options, but is probably worth it in the long run.

The VPN support in Amazon VPC is designed for hardware appliances, not what are commonly known as "road warriors". (I am further going to assume your developers aren't necessarily in the same place.)

You can run a VPN service on a regular Amazon EC2 instance, as long as it runs entirely on TCP or UDP. OpenVPN is a popular choice.

PPTP and L2TP were traditionally unavailable, as they used other protocols, which you couldn't forward to your instance. You can now forward these protocols through a VPC security group, so you should be able to run a PPTP or L2TP VPN server.

Alternatively, it may be suitable for you to have your instance in a security group and allow access to that group by single IP addresses which your developers provide for you.