wireless extender

I read the Do's and Don'ts sticky and I think I am providing the information that is pertinent to my question. xFinity (Comcast) is my ISP. I lease the modem/router/gateway from them. Router info: Model:CGM4140COM, Vendor:Technicolor, Hardware Revision:2.2. The input to the router is connected...

Just today I had set up a LAN/LAN AP for my housemates upstairs as their internet kept dropping out (and we have concrete walls so I'm assuming it's part of the problem). Instead of getting those power point extenders, we decided to connect an old router to our main router's ethernet port...