In my Ubuntu machine I have Bittorrent 1.4. In my Windows machine have 2.0. Both the devices anre linked and each of them appear in the other's peer list. But no syncing is happening! What might be the problem? The Ubuntu sync.log (a part of it) : [20150522 13:57:24.862] total physical memory 536870912 max disk cache 2097152[20150522 13:57:24.873] Using IP address 10.0.0.100[20150522 13:57:24.874] Loading config file version 1.4.111[20150522 13:57:24.874] My PeerID: 104F413AA84EC296107927846D4866371CD8C9D2[20150522 13:57:24.875] NAT-PMP: error: Not Authorized/Refused (e.g. box supports mapping, but user has turned feature off)[20150522 13:57:24.875] NAT-PMP: error: Not Authorized/Refused (e.g. box supports mapping, but user has turned feature off)[20150522 13:57:28.877] UPnP: Could not map UPnP Port on this pass, retrying.[20150522 13:57:33.883] UPnP: Could not map UPnP Port on this pass, retrying.[20150522 13:57:38.889] UPnP: Could not map UPnP Port on this pass, retrying.[20150522 13:57:43.894] UPnP: Unable to map port 10.0.0.100:22470 with UPnP.[20150522 14:17:28.889] UPnP: Could not map UPnP Port on this pass, retrying.[20150522 14:44:37.166] Incoming connection from 10.0.0.200:52389[20150522 14:44:37.167] Incoming connection from 10.0.0.200:49447[20150522 14:50:02.398] Incoming connection from 10.0.0.200:52389[20150522 14:50:52.559] Incoming connection from 10.0.0.200:52389[20150522 14:57:34.975] UPnP: Could not map UPnP Port on this pass, retrying.[20150522 14:58:27.466] Incoming connection from 10.0.0.200:52389[20150522 14:58:27.467] Incoming connection from 10.0.0.200:49478[20150522 14:58:30.494] Incoming connection from 10.0.0.200:49478[20150522 15:00:02.733] Incoming connection from 10.0.0.200:49478[20150522 15:08:29.931] Incoming connection from 10.0.0.200:49478[20150522 15:10:03.123] Incoming connection from 10.0.0.200:52389[20150522 15:10:03.124] Incoming connection from 10.0.0.200:49591[20150522 15:10:03.171] Incoming connection from 10.0.0.200:52389Windows sync.log (part of it) : [2015-05-22 15:10:00] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:01] Incoming connection from 10.0.0.100:22470[2015-05-22 15:10:04] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:14] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:24] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:35] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:44] Incoming connection from 10.0.0.100:45469[2015-05-22 15:10:55] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:05] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:14] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:24] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:35] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:44] Incoming connection from 10.0.0.100:45469[2015-05-22 15:11:54] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:04] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:14] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:24] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:34] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:44] Incoming connection from 10.0.0.100:45469[2015-05-22 15:12:54] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:04] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:14] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:24] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:35] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:44] Incoming connection from 10.0.0.100:45469[2015-05-22 15:13:54] Incoming connection from 10.0.0.100:45469[2015-05-22 15:14:04] Incoming connection from 10.0.0.100:45469[2015-05-22 15:14:14] Incoming connection from 10.0.0.100:45469[2015-05-22 15:14:24] Incoming connection from 10.0.0.100:45469