How does syncing among 3 or more devices work?

Hello and welcome to syncthing, :smile: it is fairly simple to get any number of devices to sync a folder with each other. If you set up your devices, look for an option about “introducer nodes”. Any device you select as introducer node will share its known device IDs to the other device as needed. It’s kinda like “a peer [will] automatically tell a new peer of pre-existing peers”

Have fun!

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Thanks for the reply! I’ve been playing around with it, but the mainline executable lacks a native Windows installer and the GTK wrapper - which fixes that problem - somehow results in the announce address being unreachable. Besides that, the UX of connecting devices is extremely complicated. Given that BTS 2.0 already works on my end (most of the Android & Windows launch bugs have been ironed out in the past week), I’ll have to give this a rest for now. I’ll check back later if BTS starts acting up again.


You can use Synctrazor to have an windows installer. You can download it over there.


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Thanks man! That worked perfectly on the Windows side. Now I’m just trying to figure out how to get folders I share with my Android device to actually show up in the Android client.

AFAIK the Android client does not show the dialog to add a folder which was shared with you. For that I always use the web interface, where you will get a prompt for every shared folder.

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Thanks, I tried that and got it to work, but the UX is awful to say the least, what with having to manually type out folder paths instead using a selector and all. Progress is progress, I guess.

Does the web GUI show all the peers for a given folder, or just the one(s) that was(were) explicitly connected via ID exchange? Curious because if it does that’s great for troubleshooting and seeing what’s going on. OTOH if it doesn’t it’s difficult for the user to determine sync status.

Only the ones that were connected.

eg: (no Introducers definded) A <> B, C, D <> F A is connected to B, C and D. All these 3 are connected to F. A is not connected to F All share the same folder. A cannot see (or know about) F

That makes sense. However, I was referring to the case in which all peers have been defined as introducers.

Do all introducer peers for a given folder show up in the client GUI, regardless of whether a manual Device ID exchange was done? e.g. If A, B, & C are introducers BUT Device ID exchanges were done between A <> B and A<>C only, will B show up as a peer in C’s UI?

Thanks all for your patience. I’m genuinely trying to learn the ropes.

They will all show up in your device list no matter how they were added (manual or by the introducer)

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@Alex Fantastic! Thanks man. I’ll add some other devices today and see how it goes.

So far so good. I migrated 3 Windows PCs and my Android phone to Syncthing today.

@bigbear2nd (or anyone else) what’s the best way to get Syncthing up and running on Linux Mint such that it runs at login like Synctrazor does?

For more detailed information about the introducers, you can have a look here: (shameless selflink:)

For Linux I definitely recommend syncthing-gtk. While you seem to have had some bad experience with it on Windows, I run it on several Linux-machines (Mint, Arch, Ubuntu) without a problem.

If you are using a distro using systemd, just enable it:

I have a question regarding the orriginal topic with introducer.

Say I have a configuration where A is connected to B and they are both marked as introducers, then C and D gets connected to A, at the same time E and F gets connected to B.

C, D, E and F are not marked as introducers, in the event that A should be down, automatically C and D should sync with B untill A gets online again and starts to sync with B.

In the event that A and B both are down, will C figure out to sync with say F?

To make it less typing let’s scrap D and F.

So for you to add C, you will have to restart A, once A restarts and connects to B, B will add C. C will not add B, because from C’s perspective A is not an introducer, hence C and B will not sync.

Hence no.

But as soon as B adds C, B will figure in C needed to be accepted, and from there on C and B should both know of each other.

Or not?

Because this is the behaviour I see on all my nodes when I make a reinstall creating new identity on one of the devices.

No, C will not add B, as C does not mark A as an introducer, hence it will have to be added manually/via the prompt.