How do I sync data between multiple Synology NAS via Synology Drive Server?

Purpose

With Synology Drive ShareSync, you can seamlessly sync data among multiple Synology NAS devices.

The following terms are used in this article:

Local Synology NAS: The NAS on which you are operating Synology Drive ShareSync. Data on this NAS will be synced with another NAS.
Remote Synology NAS: The centralized NAS with which you wish to sync data on the local NAS.

Before you begin, make sure you have completed the following:

Synology Drive Server (available from Package Center) has been installed on all Synology NAS devices that you wish to sync with.
You have enabled the shared folders you wish to sync as Team Folders in Synology Drive Admin Console > Team Folder on the remote Synology NAS. Refer to this article to learn how to enable a Team Folder.
You must sign in to the local Synology NAS using an account belonging to the administrators group to create Synology Drive ShareSync connections.

Please follow below instructions to establish a connection between your local Synology NAS and the remote Synology NAS.

On your local Synology NAS, open Synology Drive ShareSync, enter the IP address (or the QuickConnect ID), username, and password of the remote Synology NAS.
- For domain users, use your "domain name\username" to log in.
- For LDAP users, use "username@Base_DN" to log in.
- IPv6 or proxy connections are available.
- Port forwarding is required for connecting to a remote Synology NAS in a different network. You need to configure the remote router to forward connections to the remote Synology NAS through port 6690. Refer to this article for more information.
- If Synology Drive ShareSync fails to verify the SSL certificate, it likely has an untrusted self-signed certificate or someone may be trying to intercept your connection. You can apply for a Let's Encrypt certificate for the domain name on the remote Synology NAS. Refer to this article for more information.
Choose the remote and local shared folders you want to sync, tick the checkbox Enable, and click Done. For more information about setting options, refer to this article.
After the setup has been completed, a new connection will appear on the left panel in Synology Drive ShareSync.
You can either create more sync tasks with the connected Synology NAS, or add a new Synology NAS by clicking in Synology Drive ShareSync and repeat the steps above.

Notes:

If you use Hyper Backup or Migration Assistant to duplicate the Synology Drive Server package to another NAS, and create a sync task between the source and the destination devices, you may encounter the message "You can only enter the IP or server name from another server". This is because the package was duplicated from one device to another, causing the package to identify the two devices as the same. To solve this issue, remove the Synology Drive Server package along with its database from either NAS and reinstall it again.