Force Sync


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Greetings, all!


I am new to the forum, looked at the FAQ, and tried to search for an answer to my question, in case one already exists, but may have missed the answer anyway.


My situation is this: I have BitTorrent Sync installed on several machines, sync-ing several (large) directories. At least 3 of these machines are Mac laptops which change location and IP addresses "very frequently" (on the order of a couple times a day, each). At least 2 of the machines are "servers", with fixed IP addresses. The problem is that when the laptops change location it often takes "forever" for them to find their peers. I set the folder_rescan_interval to 60, but that didn't seem to help -- I had hoped it would force the machines to announce themselves and sync more frequently, but it doesn't seem to have done "anything" (except, locally, perhaps).


I am wondering: Is there a way to force BitTorrent Sync to find peers and sync? (Actually, how are peers identified and is there any way I can speed that process?) Alternatively, is there any way I can tell BT Sync "look here" (there's a peer at this IP address)? Or some way I can tell BT Sync: "this machine will 'always' be on-line at this address, go ahead and sync every M minutes"?


I understand that this is a peer-to-peer architecture, but I am hopeful that someone has some advice for me. (Probably, some mechanism I haven't even thought about yet).


Happy to answer questions if I have left out something important.


In advance, many thanks.


Hope all's well,



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Sync uses different mechanisms for discovery of peers in LAN and over WAN. I suggest that your peer are connected over internet. In this case every peer completes 2 steps to discover others:


1. Get the file "", find out what is the IP of a tracker in the file

2. Contact tracker (TCP or UDP over port 3000) to find out where are other peers located


I suggest that your migrating laptops fail with step 2 (it is very unlikely they can't get the file over http). Please make sure that the port 3000 is allowed in the locations where you connect laptops.


As for the predefined hosts - yes, it is going to work as well. In this case peers will try to connect directly even if tracker server is not accessible.

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Many thanks for the help and explanation. As an update, the "use predefined hosts" seems to have solved the problem (for now?) and everything is working as expected. Port 3000 was open to and on both servers, but somehow this didn't help. I didn't do much analysis of the problem, unfortunately. Thanks again.

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  • 2 weeks later...

Port 3000 was open to and on both servers, but somehow this didn't help.

You only need an open port on the listening side. In this case, the tracker port is a remote server, your btsync clients have no problem connecting to them. The tracker is listening on port 3000. Your clients aren't trackers. They do listen on a port however, which you can set to a static one in the settings (as I understand it, and it seems to do what I expect that to do), in which case you don't need to use uPNP. For each client's listening port you *do* have to open the port through NAT on your router or firewall. That's from the outside in, so the outside sees that btsync is listening on that port.
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