Right now I have the Deco1 plugged right into my ISP Modem/Router

Modem/router --- Main Deco then Deco2 & 3 are placed around the house.  They extend my network great. .

Problem.

I have a wireless printer on that Wireless Network.

I have two computers hooked to the Modem/Router and because the main deco creates its own network I can not access that wireless printer.

I tried hooking a switch to the 2nd Ethernet port on the Main Deco and hooking my two computers to that but it did not work. 

Thoughts?

Question.

Why does each Deco have two ethernet ports?