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reply to KevTech

Re: [Connectivity] MAC Address Scam?

said by KevTech:

You say this is a new modem and then say you can not get a refund.

Why could you not get a refund if the modem was just purchased?

We have a winner!

Mike Wolf

Beachwood, NJ
reply to rody_44

If service was never activated then I'm surprised they didn't blacklist the account from being able to activate service for lack of compliance. :/ Glad they didn't though.


Portland, OR
reply to Kaddock

Wow! What a flurry of answers. Thanks! OK, let me clarify here -

I never stated I can't get a refund - I purchased the item off of Amazon and have contacted Amazon and the seller. It's a holiday in the states, so I don't expect a response until at least regular business hours tomorrow. We'll see what they say.

Here is my argument - I understand that it would be easy to rip the labels off of a Comcast modem and find a box for it. The issue here is that I also have an official Motorola document which has a label / certificate which is identical to the label on the modem showing serial numbers and mac addresses. It would take an extremely good fake to create a label of authenticity like this one, and frankly, there's another obvious point - you don't receive authentic documentation with a Comcast modem. They just drop it off with their sticker on it. If this was stolen, it would have no documentation linking to it as an original purchase. I don't buy it.

I've been reading into this, and have found several articles of info on the internet which imply that people are sniffing mac addresses and somehow using them and screwing people. Is this faulty info? I'm confused as to how this would work, since it is burnt into the ROM of my device. Whatever the case may be, I've read that others have had this problem, and had Comcast confiscate their devices. I'm not letting them touch mine without some proof.

Thoughts? I'll be hitting the Comcast store tomorrow to bring my authentic documentation to their attention. If they won't remove it from their blacklist, I guess I'll go from there...


Pleasanton, CA

Generally it's pretty easy.

All you do is open the modem and then attatch either a usb jtag device or connect straight to a parallel ports with a few resistors and dump the nonvol.

Wait until a person subscribes to Internet, then you load that nonvol onto another identical modem, and you have a clone.

However, this is stupid, since Comcast already has implemented clone detection since forever ago.

(1 year at least)

Hence you may have got that call.

If it's not directly from amazon, or prime labeled, I don't like buying anything from them.
Amazon/prime sellers are too epin, 1 day replacements, free shipping and free returns.


reply to Kaddock

My real question here is how is a gateway from motorola that is doc 3 get blacklisted? So blacklisted seems like it may be a bad term. It is possible, this was someones personal modem they sold, and in doing so never removed from an account they had with comcast. It is also possible that account went over bandwidth limits repeatedly and got some sort of banning. But this should all be clearable at a local office with ID if that's the case. Save for one issue. This creates a conflict in the equitpment system as the same modem cannot be on 2 accounts even if one is terminated. If that is the CASE, have the seller get the modem removed from his comcast account he should just have to call in to do it [I agree its BS, I fight this every day on installs and it pisses me off to no end how stupid it is, but its the way it is and no matter how much we have bitched no one has ever taken the initiative to fix it, generally I am dealing with one person who moved across state lines taking their modem with them but it never works out as easily as it should.]. If you are paying for service, and are live, hook the modem up, you should get a provisioning page once it locks in and firmware updates are done. Enter your account number, and phone number associated with the account [they can even give you this over the phone if you do not have it on a bill]and go through the provisioning setup, worst that can happen is nothing. Best is you get the bug I see ever so often and get the modem provisioned and working and they keep a place holder on your account instead of the modem mac. Good luck.

PS the paper work has nothing to do with what the children claiming to hack modems were saying you do not need it technically to provision a modem it is related to what the government would do when they found out you did it as its against laws. but.. That's a moot point right now.

I am making a couple of assumptions 1 is this modem is brand new to you, and you have not had it online for a few months and been blacklisted for excessive bandwidth usage. 2 is the modem is not stolen from someone who has Comcast working with them to recover them. 3 is that the MAC banning will be done through the local cmts only and not on a regional or national level. try to provision it with the walled garden site and see.

Fort Lauderdale, FL
reply to Kaddock

Well, as you already know or know now, Amazon is a storefront operation that handles sales for other merchants.

I have bought several DSL modems via Amazon in the past, all claimed to be new in box. But they weren't. They were refurbished and re-boxed in non-retail OEM white-box packaging.

How do I know they weren't new and previously used? Easy. They were not reset to factory defaults and contained the previous owner's ISP PPPoE login credentials. Otherwise they were perfect, not a scratch on them which leads me to think the cases were replaced with new ones.

This is probably what you have, a previously owned refurbished modem that Comcast has decided to blacklist for some reason. They do not just invent MAC addresses to blacklist - they can't even begin to know a specific MAC address until it is provided to them by someone trying to use the device on their service. Another possibility is they made a typo when they blacklisted another MAC and yours got entered instead.

You are certainly entitled to a refund from the merchant. But you may never get an explanation as to exactly why your modem was blacklisted.

Good luck.


Portland, OR
reply to Kaddock

Hello Everyone -

Problem solved. Comcast is completely full of it... The seller sent both them and I a copy of his best buy receipt, and I went into the Comcast store to verify that all was good. The tech at the counter told me that Comcast does not even use this specific Motorola modem, and he didn't see it in the system.

I have no answers, but I have a success story.

As long as I have your assistance - does anyone know of a really good setup guide for the router settings on Motorola SBG6580? I am having a heck of a time forwarding ports through this router. It was sooo easy on my last one. I wouldn't mind a for-dummies walk-through on the firewall, forwarding section, etc.

Freedom is NOT Free
The Boro
·Cingular Wireless
·Comcast Business..

said by Kaddock:

As long as I have your assistance - does anyone know of a really good setup guide for the router settings on Motorola SBG6580? I am having a heck of a time forwarding ports through this router. It was sooo easy on my last one. I wouldn't mind a for-dummies walk-through on the firewall, forwarding section, etc.

I can't guarantee how good (or accurate) it is, but: »portforward.com/english/routers/···SBG6580/ might provide you with a starting point.
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

Carpentersville, IL
reply to Kaddock

If the link I'm posting is right, it should pull up the User's Guide for your modem.

I got this by going to the page that I referenced, then clicked on the "get help" button, and selecting "user's guide" from the topic drop down.


If that does not work, I've "attempted" to attach the PDF to this post. Not sure if that will work or is even allowed. This is the first time that I can think of that I've "attached" anything other then an image.

--Brian Plencner

E-Mail: CoasterBrian72Cancer@gmail.com
Note: Kill Cancer to Reply via e-mail


Portland, OR
reply to NetFixer

@ NetFixer and plencnerb - Thanks for these!

@ Everyone - thanks for being very attentive. This is a great forum!


Fremont, OH
·AT&T U-Verse
reply to DataRiker

The OP did NOT say he could not get a refund. He said this:

Can someone help me understand this? Is there any way to hassle Comcast into launching an investigation? I can't afford to buy another modem if I can't get a refund, and honestly, Comcast should have to help me deal with this!!!

With the key word IF

Naples, FL
reply to plencnerb

said by plencnerb:

First off, I did some research on the OP's device. I'm calling it a device, and not a "cable modem", because of what I found out.

My information comes from this page


No normal "Cable Modem" has four 10/100/1000 Gig Ports on it, along with 802.11n wireless technology.

This tells me that the OP has a "Combo" or "Gateway" device. They don't have a "standard cable modem". What I mean by "standard cable modem" would be one like a Motorola Surfboard SB5100.

Since the OP has not said where they "purchased" this "new Motorola SBG6580" from, anything we post here is just assumptions.

However, I will say that it is quite possible if the OP did purchase it from a friend, or online from Craigslist, ebay, or other like website, there is a good chance that Comcast has "blacklisted" the device. The reasons for that action by Comcast have already been listed by graysonf See Profile.

I also agree that there is no way to change the MAC address on a standard cable modem. Modifications to the MAC address of a router are possible however. In fact, I remember back in the day when I first got cable internet (ISP was @home), I had to "clone" my MAC Address of my PC into my router, as the modem would not allow me to go online, as I had to register first using a PC without the router. Once I added the router (which, btw was a Netgear RP114), there was a place in the router to "clone" the MAC of a PC (or you could just type one in). In this way, that MAC was passed onto the cable modem, and all was well. I don't believe one has to do that anymore.

Could the MAC on the router side of the OP's device be modified? I believe so. But, that's not the reason the OP cannot use it.

If the OP does respond, and they tell us that they purchased it new from a brick and mortar store (Best Buy, Wal-Mart, etc), and shows us proof of such transaction, I think it would be time for the OP to return the device for a new one, as it would appear that the "new" item was not really new.


That page clearly states it's a cable modem, it just happens to have a wireless router built in. My last CL Cisco modem had a built in wireless router as well.

The wings of love
Union, NJ

1 recommendation

They use the incorrect term IMO. It should indeed be considered as being a combo modem /router *gateway device*.