Feature availability depending on Resilio Sync version
Resilio Sync v3: fully available.
Resilio Sync v2: available in licensed Resilio Sync version (Home Pro or Business).
Sync Identity is one of the most powerful features available in Sync.
Each and every Sync installation gets a unique digital certificate generated based on the selected identity name. This name will be used to generate digital certificate and random fingerprint for your Sync instance. Even if you give same name to two independent Sync instances, their certificates (identities) will still be different. The certificate helps to identify the peer when it connects to a share, and its fingerprint can be viewed by clicking on "ⓘ" symbol to the right of the Identity name in "Preferences -> Identity " menu. These will be later used for further connection to other peers - seeing the fingerprint and the name others will know which Sync installation is trying to connect to them.
You can select any name by which other peers will be able to recognize you and know that it's your Sync that is connecting to them. Identity name cannot be blank.
Easier security: Once a remote user approves a connection to one of your devices, they can choose to automatically approve you on all your linked devices for any future sharing.
Universal access: Once you get your devices linked, all of your Sync folders will automatically be available from any of those devices.
Faster approvals: When you receive a folder access request from a new peer, you'll be able to approve them from any device where the folder is in the "Selective Sync" or "Synced" mode.
Versions compatibility
It's highly advisable not to link devices where Sync of different versions - v2 and v3 - are installed. If linked, they may conflict on the applied license and lead to lost access to Sync UI and shares configuration. Files on the storage will not be affected though.
Creating certificate
Start Sync, type in your name and agree to Terms, Policy and EULA. When you click "Get Started", Sync will generate your unique digital certificate - "create identity".
If you mis-typed your name or simply would like to create a new one, first you'll have to unlink this device. Click here for instructions.
Linking Devices
Now that the identity is set and certificate is created, you can start linking all your devices to it. When your devices are linked, every time you add a folder on one of your devices, it will AUTOMATICALLY be available on all the other devices, that is, ALL the folders will be visible and accessible on ALL linked devices and no additional links or keys will have to be sent.
If you already have some shares configured in Sync on device1, it's important if you link device2 to device1 or vice versa. If you take the M-key from device1, and use it on device2, the latter will take the identity name, fingerprint of device1 and get all the configured shares from device1.
Sync will provide you with several synchronization modes for each of your devices, thus letting you choose how much data (if any) Sync will be fetching to this or that device every time a new folder is added on the other devices. For more information regarding synchronization modes, click here.
To be able to link other devices to this one, apply the license key to this Sync instance or enable Pro Trial. After getting Pro, go to Sync settings -> Identity -> Link device. (in Sync Free the Link device button is dimmed, greyed out, share each folder manually instead). Here you can also see the list of all linked devices.
Sync will offer two options:
Option 1) scan a QR code with a mobile device to link that to this computer.
Option 2) link a desktop device manually – use this option to copy/paste the M-key and link your desktops and laptops.
"Copy key": copy the M-key (shown above the button), deliver it to remote device so that remote device links to the current one.
"Enter a key": paste the M-key taken from remote device so that this device links to the remote one.
It may take your devices a little bit of time to get linked, but once the connection is established, a new window will pop up suggesting default folder location and prompting three states of synchronization: Disconnected, Selective Sync and Synced (click here for more details).
If you would like to link additional devices - whether it be desktop computers or mobile phones/tablets - simply repeat the above steps: take the M-key and deliver it to the device that you want to link here.
The linked devices show up in the list, each device has it's name and shows the selected synchronization mode - Disconnected/Sync All/Selective Sync. You can click on a device with "Sync All" mode and see its storage status. Grey/greed dot indicates if device is offline/online.
Unlinking device
You can unlink this device at any time, however, in this case, all connections to other peers will be lost, and you’ll have to create a new Sync identity or link this device to another device on which identity is already set. Also note that you cannot remotely unlink other devices.
To unlink this device, go to "Preferences -> Identity -> Unlink from identity".
If one or several of your linked devices go offline and are not in use for a while, you can clear them from the device list. Click here to learn more.