I have BtSync set up on a handful of machines and it's working great: Debian 7 (x86) - 192.168.10.102 Debian 7+ (Testing) (x86) - office computer Android 4.2 - 192.168.10.105 Android 4.1 - 192.168.10.106 This machine doesn't work: Debian 7+ (Testing) (x64) - 192.168.1.100 Network setup: Internet > 192.168.1.0/24 Router, anything on this network BtSync won't work > 192.168.10.0/24 Router, anything on this network BtSync works fine On the problem machine (192.168.1.100), I cannot get anything to connect outside of that subnet. The router has UPnP enabled and netstat shows the btsync