I have 3 deco M4 and 1 E4. I use 1 main deco connect to isp router by LAN port in front room at 1st floor. 1 slave M4 in my kitchen room at ground floor, another slave M4 is in my bedroom (back room at 2nd floor), E4 is in my front room 2nd floor. I use LAN cable connect to wall jack to switch TP-Link SG1005D --> Lan cable to main M4 (distance from slave M4 to main M4 around 20m). Deco M4 has 2 mode (router wireless and access point)

- Router wireless mode : Slave M4 in my bedroom (2nd floor) don't use ethernet backhaul to connect with main M4. It just use wireless to connect to another deco. I tested another wall port in back room at 1st floor (distance around 10m) slave M4 use ethernet connect to main M4.

- Access point mode : Slave M4 in my bedroom (2nd floor) use ethernet to connect with main M4 (the same place in my bedroom at 2nd floor with M4 in router wireless mode)

How can i set my slave M4 in my bedroom connect to main deco M4 by ethernet? Because with ethernet connection i'll use nearly 100% bandwidth of my ISP line. Is there any firmware which can let user like me define ethernet/wireless connection between slave and main M4? I've already called to support of Vietnam Tp-link but they don't know how to help me solve this?