The "Connection Tracking" portion of http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network-security.html http://docs.aws.amazon.com/AWSEC2/latest/Use

The "Connection Tracking" portion of http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network-security.html http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-net... provides some insight here and describes a method to avoid connection tracking in EC2's firewall.