I fight with Cox on a weekly basis (work for an MSP). They are a terrible company. Cox will let you bring your own gear and I advise you do. Fuck paying rent for a modem/router only to have them turn on a guest ssid. I heard this news weeks ago and I couldn't believe it. I'm not sure how this isn't illegal. What if someone connected to your shit, and downloaded a bunch of illegal stuff?
check my original post but TLDR it has it's own IP addresses, it has absolutely no direct connection to your personal network and it doesn't effect your connection in any way. comcast has been using it for years without any issues.
and you can disable it..