We are building a web app using Amazon EC2 instances running Linux. All the traffic to the client browser is encrypted with SSL. What should be used to encrypt the traffic between the instances.
The traffic will include connections to a MySQL database from Tomcat as well as file transfers.
It needs to be reliable and reconfigure itself if it fails.
Best Answer
My understanding is that EC2 instances act as though they are independent servers on a switched network, so traffic should only going to and from your instances if it's supposed to be there, and not visible to any other instance aside from the source and destination within their network, so the level of security you're looking for may be overkill.
Having said that, take a look at scp for copying files between instances as it will provide encryption for you. MySQL 5 also supports SSL between clients and the server.
If you just want to encrypt all traffic, regardless of use, a secure site-to-site VPN may be an option.