what I did initially: 1) created an ec2 instance, installed btsync, configured listening port, opened it in security policy etc. I validated that it works with btsync installed on my laptop. All files were synced to ec2 (and back) 2) I created an image of this ec2 instance with btsync already installed 3) used this image to create second ec2 instance (btsync was cloned with all files from 1st instance, including initialized .sync folder) after that, both instances were syncing properly with my local btsync, but they never talked directly to each other, even when I set 'preferred hosts'. files were transferred always via my laptop. when I switched off local btsync, no syncing was happening. no errors in logs either. I was removing/adding folders back, changing ports, nothing worked. however, when I stopped btsync on the second instance, removed .sync folder, started btsync and added back all folders, suddenly everything works fine. I guess this issue will be very easy to reproduce. I've done it couple of times today, always with the same result (luckily the last time I created a fresh instance and that gave me a hint that something smelly is going on with pre-installed btsync) thanks