@Hansontech I remember that how to set LAG also has a FAQ on the TP-LINK website, you can check the settings by looking at this: https://www.tp-link.com/en/support/faq/2396/

@DQP You can also think differently, e.g. set up PPPoE + VLAN on the modem router to work normally as a router, and select dynamic IP as the network connection type for the ER605. You may have a try.

@PaulTA You can check if the EAP on the controller shows disconnected or something else. Also check whether the PC can get an IP and whether the EAP can get an IP from the DHCP server. I think using...

@Einnaro The WAN status on the system status page should be the physical status. The online detection is based on the ping result to determine whether the WAN is disconnected. You can set it to...

@dotcommer I wanna know how you make the IP is reserved for EAP (on the controller?). And is there an Omada gateway in your Network topology?

@Hansontech Based on your mentioned information, your two SG2008P's are required to be set the LAG. By the way, it is advisable to upgrade the firmware version of the EAP235-WALL to the latest one....