@Ericd2011 

Hi,

The network topology would be fine.

Since it requires the Ethernet backhaul between Decos and the network switch is needed, some switches could not use to create the Ethernet backhaul, such as D-link switches;

https://www.tp-link.com/support/faq/1794/

Q4: Why my Deco units become unstable once they're connected via a switch?

It's probably that you're using a D-Link switch.

The Deco Ethernet backhaul feature is based on the standard IEEE 1905.1 protocol. However, we find that some D-Link switches will not forward packets based on IEEE 1905.1 protocol, causing all Deco units in a network loop and becoming quite unstable. If you have a D-Link switch and encounter an unstable issue with Ethernet backhaul, we recommend changing the switch to another brand or contact D-Link support directly for a fix.

If you're not sure which switch to use, TP-Link switches may be a good choice.

Thank you very much and wait for your reply.