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#36512 by kb7
Wed Dec 09, 2009 2:02 pm
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.

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 (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. :cry:

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. :idea: 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." :)

#36516 by murphy
Wed Dec 09, 2009 2:17 pm
Make sure that your router isn't set to spoof it's upstream MAC address.
#36520 by kb7
Wed Dec 09, 2009 2:54 pm
murphy wrote:Make sure that your router isn't set to spoof it's upstream MAC address.

Roger that. If memory serves (I am away from the console.) the router gives me three options: "default" (which I'm not 100% clear on), "use computer MAC" or "enter you own." I believe I have it set to default. I've always assumed default=burned-in. But I am not 100% sure about this, because the really puzzling thing is *which* port it picks for "use computer MAC." I would guess the computer on port 1 (of 4) but that is just a guess. I may try entering a fixed MAC by hand.

#36579 by kb7
Thu Dec 10, 2009 8:53 am
murphy wrote:Make sure that your router isn't set to spoof it's upstream MAC address.

I have confirmed that I have both the router and the ooma using their burned-in MAC numbers. Still goes down. I have also confirmed that the start of downtime does not correlate with expiry of the lease obtained by the router from the modem. All of this is with modem-->router-->{PCs + ooma}

Since this configuration is locking up just like the recommended configuration, I have gone back to the recommended Config #1: modem-->ooma-->router-->{PCs} in preparation for generating an RMA with ooma.

Now, back in the recommended config, I expect to still have problems as I did originally. What is really strange is that when I browse from a PC to, four out of the five setup screens are completely blank. The only one which isnot blank is the Ports screen, which looks perfectly reasonable for the config I'm in.

I really think my ooma is toast, and it's landed butter-side-down.
#36585 by murphy
Thu Dec 10, 2009 9:00 am
Kaspersky anti-virus will prevent the loading of the internal ooma web pages.
#36766 by kb7
Fri Dec 11, 2009 9:51 am
Ok. Confirmed: Kaspersky blocks all but one of the ooma setup pages.

Meanwhile... the ooma has been running for over 24 hours again. This is with Congig #1 : modem-->ooma-->router-->{PCs}

During the last 24 hours time, all leases obtained by the router from the ooma have been 12-hour leases which appear to be getting renewed a little before the six-hour mark. So the ooma has stayed up through at least three consecutive downstream lease-renewals -- one of which I witnessed in person. This is all based on the router's stats. Unfortunately, neither the ooma itself nor the cable modem seem to provide user-accessible stats on leases. (The surfboard is not one of the tricked out diagnostic versions.) So I'm afraid that the next time the system goes down -- and I'm sure it will -- I will not have much to go on.

I picked up a new router last night but am waiting until the system goes down again to swap it in, on the off-chance that the next incident will provide a new clue. I doubt the router is the problem, but it's the cheapest thing to replace. :? I really don;t want to go through the hassle of replacing the modem, so I'm going to see if COX can find diagnose it remotely.

The thing I really don't get is why these service outages happen only when the ooma is involved. If I assume that COX is not deliberately messing with me for using VOIP, then I have to consider the possibility that the modem has been dropping out all along and that what would normally be a recoverable condition is made non-recoverable by the presence of the ooma.

Thanks for all the great advice. I'll post when I know more.
#39702 by kb7
Fri Jan 01, 2010 11:40 am
Problem solved by a new modem.

See thread "Ooma takes whole LAN down at least once per day" in the "Other Support Topics" forum.


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