Wan Online detection - Bug? Please help.
Model : TL-ER5120
Hardware Version : V4
Firmware Version : 4.0.2 Build 20200313 Rel.52726
ISP : Multiple
The router is set up to use 3 WAN connections, each Wan goes to a DSL or 4G Modem router prior to reaching the TL-ER5120. Since the DSl or 4G modem router may remain online when the connection to the ISP has been lost, I have set manual Online Detection to detect (Ping & DNS Lookup) 220.127.116.11....
However, of the 3 wan connections one is not being recognized as offline when it is disconnected from the ISP ... specifically from the Asus DSL-AC68U modem router. The TL-ER5120 does not detect the loss of connectivity and continues trying to route traffic through the failed WAN.
Troubleshooting so far:
-> It is not an ISP issue, as 2 of the wan connections are using same ISP, and I do not experience the issue on the other DSL-Modem Router from ZYXEL.
-> I physically changed to another wan port of the TL-ER5120 and same issue
-> Of course from system tools -diagnostics - ping of 18.104.22.168 times out on that specific Wan port even if it remains detected as online
-> I tried putting a router between the DSL-AC68U and the Load Balancer, but same issue.
Anyone has any idea what could create the issue, is there a bug?
Thank you for your help.