How to Configure Link Backup on Dual WAN Routers Using the New GUI

With the Load Balance function, TP-Link Routers can provide multi-WAN access, which not only reduces the traffic burden, but increases the overall egress bandwidth, while also automatically switching all the new sessions to another WAN when a dropped WAN is detected, thereby improving the network reliability.

Using this technology, TP-Link Routers can further provide the Link Backup function, allowing you to customize the usage of multi-WAN access with Timing or Failover modes. Simply put, only the primary WANs are used for data forwarding under normal circumstances, while Backup WANs are always on standby to start data forwarding as soon as the triggered condition is detected, such as the set time or link state change.

In summary, both functions can improve redundancy, but Load Balance will use all WANs, while Link Backup will use parts and backup other parts of WANs according to your configuration.

1. What is the Timing mode Link Backup feature, and how do I use it?

For example, a user has a TL-R600VPN V4 and there are two WAN ports connected to the Internet. They want to use WAN1 while at work and use WAN2 after work. The “work” time is from Monday to Friday 8:00-18:00.

Timing mode Link Backup can help accomplish this.

Step 1. Set up the Time Range for the Backup WAN effective time.

Navigate to Preferences → Time Range, where you can define the time range entry within the page.

Step 2. Enable Load Balancing

Choose the menu Transmission -> Load Balancing -> Basic Settings. Check Enable Load Balancing. Please note that “Enable Load Balancing” must be checked if you want to configure link backup. Otherwise link backup won’t work normally.

Step 3. Choose the Primary WAN and Backup WAN.

Navigate to Transmission → Load Balancing → Link Backup. Set up Primary WAN as WAN1 and Backup WAN as WAN2.

When there are two or more primary WANs, it you will be given the option to differentiate between two options:

1. Failover (Enable backup link when any primary WAN fails)
2. Failover (Enable backup link when all primary WAN fails).

The former will take effect when any WAN goes offline, while the latter will work only when all designated primary WANs are down.

Please note that during the effective time, the Backup WAN will be online and Primary WAN will be offline. At other times, Primary WAN will be online, and Backup WAN will be offline.

Note: If the online WAN’s connection is dropped or disconnected, the offline WAN will remain offline.

2. What is Failover mode Link Backup and how do I set it up?

For example, a user has a TL-R600VPN V4 and there are two WAN ports connected to the Internet, where WAN1 is fiber-optic access, which is paid monthly and WAN2 is LTE access, which is paid according to data usage. As a result, this user would like to mainly use WAN1 and only switch to WAN2 automatically when WAN1 is detected as offline.

Failover mode will help this user fulfill their needs. Network reliability will be increased and costs will be reduced significantly.

Step 1. Enable Load Balancing.

Navigate to Transmission → Load Balancing→ Basic Settings, then check Enable Load Balancing. Please note that “Enable Load Balancing” must be checked if you want to configure link backup. Otherwise link backup will not function.

Step 2. Choose the Primary WAN and Backup WAN.

Navigate to Transmission → Load Balancing → Link Backup. Set up WAN1 as the Primary WAN and WAN2 as the Backup WAN. Then WAN1 will remain online, and all the data will be forwarded via WAN1. If WAN1 is detected as offline, WAN2 will be online, and all the sessions will be forwarded via WAN2.

Step 3. Setup Online Detection.

Navigate to Transmission → Load Balancing → Online Detection.

The Link Backup feature works based on Online Detection. Auto mode means DNS lookup is used to detect the route to the gateway of the WAN port. If you want specific route detection, you can choose Manual mode to customize the destination IP for Ping and DNS lookup.

Both above examples use two WANs. However, you can use any or all of WANs as needed. Once logged in to the management page, the options will be readily available.