That makes perfect sense, and I appreciate the information as helpful. Unfortunately, it does not appear to be a complete explanation for my experience. I have the ooma hub set to use the built-in MAC on the MODEM port. And it stays online for hours at a time. I suppose *if* the ooma hub suddenly decided to automatically clone the MAC it sees connected to its HOME port (i.e., ignored my selection of the built-in MAC) then exactly what you describe would happen. And if that were happening, it would be a defect in the ooma hub. Unfortunately, once the ooma hub locks up, I cannot connect to setup.ooma.com (not even via the HOME port), and so I have no way to verify this hypothesis. Sadly, I do not have my own network analyzer.murphy wrote:Any time you change what is connected to a cable modem it is required that the cable modem be power cycled. A cable modem remembers the first MAC address that connects after it is powered on and will not let anything else connect. That is how the cable company prevents you from pulling more than one IP address from them. This is why it is necessary to lock the ooma to it's built-in MAC address. If left in automatic mode and it decides to spoof the MAC address of your router after having connected using it's built in MAC address, your access to the internet is immediately terminated.
Meanwhile, I am talking with COX to see if they have a log of any problems on my feed or if they can remotely test my cbale modem.
Wait!! I think I'm starting to understand how your idea makes even more sense. A key observation is that when the ooma hub goes down, **all** my internet connections go down, including the ones directly plugged into the router in Config #2, in which the ooma hub and another computer are plugged into the router, which is plugged into the modem. Offhand, I do not recall what MAC my router presents to the cable modem. But if anything -- and ooma is the only variable different from my previous LAN -- causes my router to change the MAC address it presents to the cable modem...BOOM! The cable modem cuts my LAN off from the COX network. But connections within my LAN would continue to work. This matches what I see. The question is... Is it plausible that the act of connecting the ooma to the router would induce the router to change it's upstream MAC at what appear to be random (or at least variable) intervals.
I am beginning to think that my next steps are (1) manually log the router's upstream MAC before and after outages (I can do this, because I can always connect to the router's status page) and (2) swap out the router, because even if it *says* it's using a fixed MAC, that does not mean it isn't going flaky. If all that fails, then I really will be exchanging my ooma hub.
I may be slow, but I prefer the term "deliberate."