This article applies to Omada Gateways and Omada SDN Controllers.
In certain network installations it is necessary to configure Link Backup in order to guarantee that the secondary WAN automatically takes over in the event of a primary WAN failure to maintain a stable network connection. This guide illustrates how to configure Link Backup in Controller mode.
Step 1. Configure two WANs
Go to Settings → Wired Network → Internet to configure Both WANs.
Step 2. Configure Load Balancing
Proceed to the lower section of the menu and configure Load Balancing as indicated in the instructions below. In this example, WAN2 is designated as the primary network and WAN/LAN3 as the secondary network, serving as the backup.
There are two different backup modes available: Link Backup and Always Link Primary. In the event of primary WAN failure, both modes will assist with switching to the backup.
However, there are some differences between the two.
Link Backup: The system will automatically switch all new sessions from ac dropped WAN to another WAN to ensure the network remains online.
Always Link Primary: Traffic is always forwarded through the primary WAN port unless it fails. The system will try to forward the traffic via the backup WAN port in the event of a failure, and switch back when it recovers.
Step 3. Configure Echo Server for the gateway
Go to Devices and click on the gateway to bring up the menu on the right.
Proceed to Config → Advanced → Echo Server, set the Echo server as “custom” and input 8.8.8.8 as the address.
An Echo Server will aid in testing the connectivity of the WAN ports. The system will continually ping the specified address to confirm that the WAN is functioning correctly. If there is a poor connection, the system will switch to the backup WAN.
Step 4. Configure Online Detection Interval
Go to Settings → Wired Networks → WAN Mode to configure the Online Detection Interval.
This determines how often the router performs a ping test to check for Internet connectivity.
Step 5. Verification
Go to Settings → Devices and click on the gateway to check the Details of both WAN ports.
Before configuring the Link Backup, both WANs were online. However, currently, only the primary WAN is operational, and the secondary one will only function in the event of a connection failure on the primary WAN.
To verify whether the applied settings have taken effect, unplug the Ethernet cable from the WAN2 port and leave only the WAN/LAN3 port connected to the router. Please refer to Details to verify the status of the two WANs. The WAN/LAN3 port should now be displayed as Online.
