My devices requiring 2.4GHZ work with my XB-3 modem/router. Will they also work with the XB-6 modem/router?
Thanks in advance for the clarification.
Yes, but you may need to do this;
The two WiFi bands have recently been combined into one with the Comcast gateway devices. Some devices get confused and don't know how to see / talk to combined bands.
If you are not using any Xfi Pods, you can try separating the 2.4 and the 5.0 bands and give them two different broadcast names / SSID's;
Associate the devices with the 2.4 band's SSID (broadcast name) and password.
I have a 6 and gave the two frequencies different names and they work fine. I have no idea if you use the quick link by pushing the button on the modem which frequency it will try to attch to so you might have to go inro the utility (10.0.0.0) and add your devices manually by adding MAC addresses.