RT-AC86U WAN Port intermittenly goes down

[Youst]

Hello,

I am having a AC86U and the WAN Port is keep bouncing few times a day and only few seconds each time.

Apr 28 03:32:08 kernel: eth0 (Int switch port: 3) (Logical Port: 3) Link DOWN.
Apr 28 03:32:11 kernel: eth0 (Int switch port: 3) (Logical Port: 3) Link UP 1000 mbps full duplex

The cable has been replaced few times and also I called my ISP replaced modem 2x but issue remained, if I connect my old linksys router, it never drop, it seems this AC86U keep taking down the WAN port, so wondering what could be the reason?

Thanks.

 

[K-2SO]

To isolate WAN port issue setup temporary Dual WAN with LAN port as main WAN. Use the router this way for a while. Check if disconnects happen again. I had one RT-AC86U replaced with failing WAN port.