[kchoudhu]

We've found OpenVPN to be our friend here: create an overlay network that doesn't really care if nodes are bare metal or "cloud".

[gerhardhaering]

I thought about that too, but as far as I see with OpenVPN you have the single OpenVPN server as single point of failure and all the traffic goes through the server, which quickly becomes a chokepoint. If I needed this again, I'd try out tinc first. It does not appear to have the single point of failure issue.

[kchoudhu]

We have multiple standby servers to prevent the SPOF issue.

One problem we HAVE seen is a reduction in maximum bandwidth. Since we're CPU limited, however, it hasn't really been an issue.