I have been running a Deco M4 mesh network for several years with no problems, but recently I have been getting a red light on my main router with increasing frequency (now about once every 10 days).  When I was able to pick up a set of X3400 Pros at a good price I thought it would be a good idea to replace/upgrade the mesh.

I have decided to make a clean break (new SSID name, new password) and make everyone re-authenticate to connect to the network.  But I have started thinking (sometimes dangerous) that if the older units are compatible with the new X4300s I could use them to cover some weak/dead spots that are a mild annoyance.  I have a stone house with a central brick/stone fireplace that makes getting signal throughout the hose (and especially into the garage and backyard when we have family get togethers challanging.  So if I could add one of the older units in a window or via a temporary cable it could solve the problem.

I strongly suspect that pwerformance would be degraded when connecting thru the M4 units, but since I go back to the days of 100mb (and even 10mb) I can be forgiving of performance in the name of convienence.

So will the two models work together in the mesh?