Initially, the Synology Bond need to be prepared for LACP (IEE 802.3ad). This can be done via Control Panel – Network – Network Interface – Bonded Interface (if already created, otherwise you need to create one). Select IEEE 802.3ad Dynamic Link Aggregation for the Bond interface and apply the configuration.

Because the switch is not prepared yet, the Synology will provide an error message which states that the LACP LAG cannot be created. No worries, this will be fixed automagically after the UniFi switch has been properly configured.

The next step is enabling the 2 switch ports where the Synology is connected for LACP. Login to the Unifi SDN controller, go to your device (switch) and open the ‘port configuration’ for the switch.

• Choose Aggregate as the operation mode
• Define the ports that need to be aggregated (only need to be set on the first port)
• Apply the config

With these settings, the UniFi switch has been enabled for LACP for the defined ports. And the LACP enabled Synology bond will recognize that and apply it for the Synology as well.

If you have any questions or remarks, please let me know!