router: Use Computer MAC Address

[jcarrera]

I have a puzzlement that I just want to understand...

A friend moved here to a Brighthouse.roadrunner location. Ordered up broadband internet and it was installed. Worked fine with direct connect to cable modem--Terayon brand.

He bought a Netgear wireless router and asked me to set it up. I am a former CCNA and am pretty darn up on networking. I did the setup manually (the Netgear dummy disk won't work with Vista 64 bit). Could not get anything other than a "local only" connection. Router page could be accessed, but router ping returned General Failures. ipconfig /all looked perfectly normal.

After finally admitting defeat (hard to do--never been defeated on something this simple before), I called Netgear. The clue to making it work was setting MAC address to "Use Computer MAC Address" rather than default!

What I don't understand is that I also am on this exact same provider (live 3 miles from friend's house), and my setup works fine with a Netgear router set to default MAC.

I understand MAC registration limitation by some providers. I don't understand why his IP service was restricted to the computer's MAC and mine is not. I have a different brand cable modem, but the MAC limitation is a provider policy thing (we are only going to send service to the MAC we have recorded for this user)--not a router-dependent thing, right?

Any insight?

 

[Pepper]

In your case, was the router already there when service was established? In that case it is the MAC that the cable company knows about.

 

[jcarrera]

No, the router was bought a few days after installation.

But, in my house, the router was changed a couple of times after original installation, and yet service continued.

Why do the providers even tie the service to a particular MAC on the downside of their "modem?" It creates these unnecessary situations to restrict the user to a single specific device that can be plugged into their modem. Seems pretty dumb to me. I must be missing something.

 

[iwc5893]

No, the router was bought a few days after installation.

But, in my house, the router was changed a couple of times after original installation, and yet service continued.

Why do the providers even tie the service to a particular MAC on the downside of their "modem?" It creates these unnecessary situations to restrict the user to a single specific device that can be plugged into their modem. Seems pretty dumb to me. I must be missing something.

It could have something to do with their billing software and how they set up their networks. You may be on an older network that doesn't require MAC address authorizations, while your friend might be on a newer one that does.

I know at my ISP, if we don't have your MAC address on file the only page you will get is a redirect page that says to call us. We do it this way because the billing software we use requires a MAC address for whatever is connected to our equipment.

I usually explain it to customers as a way to help prevent theft of service from us and from the customer. Since the customer is responsible for any traffic that comes from their connection, they can be held liable for what their neighbors do on their wireless router if it is not secured properly.

Another possibility is that they're limited on the number of IP addresses they can hand out (again, it could be affected by the billing software), and they're doing it as a way to reduce the number of IP addresses assigned to individual customers. Even NATed networks can have limits on the number of IP addresses assigned to a specific network, depending upon how the network range is setup.

 

[jcarrera]

...I know at my ISP, if we don't have your MAC address on file the only page you will get is a redirect page that says to call us. We do it this way because the billing software we use requires a MAC address for whatever is connected to our equipment...

Wow, that brings up all kinds of questions and comments
1. MAC addresses have no reason to be connected to billing whatsoever. Thus the obvious question is why was that built into the billing software in the first place?

2. OK, redirect if if no address on file. What if the address that connects is different from the one on file?

Friend did not get a redirect--he got a no connect situation.

Your company's policy means a house with a router's MAC as the registered-with-you address cannot change a failed router or upgrade without getting you involved. It also means they could not connect a computer directly to the cable modem (no router) without getting you involved. That incidently, is the FIRST thing tech support does at our ISP if you call for help...disconnect from the router and connect directly to the modem. The MAC registration approach totally complicates that.

With all the trouble it causes, I still don't see why they do it. Saying "the billing software requires it" still leaves the question of "ok, why?" still on the table.

 

[iwc5893]

If you change equipment, you get the same redirect page.

The billing software requires the MAC address because it is the billing server that hands out the NATed IP addresses and because there needs to be a way to shut off service to those customers that go delinquent and don't pay their bill.

Yes, every time a customer wants to change computers, they have to give our tech support center a call. In addition, as part of the trouble shooting process, tech support will add the computer MAC address to the system while they are on the phone and remove it once the call is over.

In addition, on our system, cloning the computer MAC address will not work. Somehow our billing software sees the cloned MAC address and throws up an error resulting in the customer getting the redirect page.

I'm not saying that this is the case for your friend, but it may be.

 

[jcarrera]

What does needing to shut off delinquent customers have to do with needing to know the MAC address connected to the cable modem. Just disable it on your end, or signal the cable modem to not transmit any traffic. MAC of connected device is not needed to do that.

Or just send no traffic to the MAC of the delinquent customer's cable modem. Again, MAC of connected device is not needed to do that.

Try again.

 

[iwc5893]

What does needing to shut off delinquent customers have to do with needing to know the MAC address connected to the cable modem. Just disable it on your end, or signal the cable modem to not transmit any traffic. MAC of connected device is not needed to do that.

Or just send no traffic to the MAC of the delinquent customer's cable modem. Again, MAC of connected device is not needed to do that.

Try again.

We don't use cable modems. I was just trying to explain a possible reason for it but I don't work for Brighthouse so I don't know the exact reason. If you really want to know the answer, maybe you should call them instead.

 

[jcarrera]

Don't use cable modems? What then does a customer's wireless router (or computer, if he does not use a router) connect to in your system? Are you a DSL provider? I am now totally confused.

 

[iwc5893]

Don't use cable modems? What then does a customer's wireless router (or computer, if he does not use a router) connect to in your system? Are you a DSL provider? I am now totally confused.

We're a WISP...our antenna plugs directly into the customers router or computer via a CAT5 cable and a power supply adapter.

 

[tobifelinis]

Ahhh I am sorry sir but there is no way to just plug an antenna into a computer and get it to work over a wisp. It has to go thru some sort of radio transceiver and modem. People who read this forum are not blond bimbos. Could you perhaps use correct terminology.

I think your credibility may be declining.

 

[iwc5893]

Ahhh I am sorry sir but there is no way to just plug an antenna into a computer and get it to work over a wisp. It has to go thru some sort of radio transceiver and modem. People who read this forum are not blond bimbos. Could you perhaps use correct terminology.

I think your credibility may be declining.

Then perhaps you should research Motorola Canopy Subscriber Modules because that's what we use. The radio transceiver is built into the antenna that we mount on the house, and we do NOT use a modem. We run a CAT5 cable from that subscriber module to the customer's computer or router, with a power supply adapter inserted inline...just like I said we did.

Or are you going to insist that my credibility is declining because I actually know what I do at work every day? Just because you are not familiar with a concept or a practice doesn't mean that it's not done that way.

 

[primestar31]

I have a puzzlement that I just want to understand...

A friend moved here to a Brighthouse.roadrunner location. Ordered up broadband internet and it was installed. Worked fine with direct connect to cable modem--Terayon brand.

He bought a Netgear wireless router and asked me to set it up. I am a former CCNA and am pretty darn up on networking. I did the setup manually (the Netgear dummy disk won't work with Vista 64 bit). Could not get anything other than a "local only" connection. Router page could be accessed, but router ping returned General Failures. ipconfig /all looked perfectly normal.

After finally admitting defeat (hard to do--never been defeated on something this simple before), I called Netgear. The clue to making it work was setting MAC address to "Use Computer MAC Address" rather than default!

What I don't understand is that I also am on this exact same provider (live 3 miles from friend's house), and my setup works fine with a Netgear router set to default MAC.

I understand MAC registration limitation by some providers. I don't understand why his IP service was restricted to the computer's MAC and mine is not. I have a different brand cable modem, but the MAC limitation is a provider policy thing (we are only going to send service to the MAC we have recorded for this user)--not a router-dependent thing, right?

Any insight?

His cable modem "married" itself to his pc, since it was the first device it saw. After that, the router will only work after cloning the pc's MAC address. Not all cable modems do this, but a lot do, and I'm pretty sure the ISP can clear this by re-initializing the modem. But, their easy answer was for you to clone the Mac addy. Very common issue, and a CCNA should know that. But, I've been a tech for almost 30 years, (21 for pc's) and I still see new stuff from time to time, so I know how it goes!

Cable MODEM"Married"to an Ethernet MAC Address

I just had the same problem a week ago with a SB 5101 modem, and it took me hours to "unmarry" the modem from my pc's Mac addy. I finally had to have my ISP reprogram the modem. Diagnosing things like this are enough to make you feel really, really stupid, when you finally get it working, and it turns out to be SO simple, you totally overlooked it... Mostly because you tend to go over and over the same type fixes you know, but in slightly different ways, until you box yourself in, and think you've covered every possibility..

 

[jcarrera]

2 things...

a. It was not the ISP that told me to use the "Use Computer MAC Address" setting; it was Netgear support.

b. My networking experience did not involve interfacing to consumer level devices at all--and especially cable modems. I understand the architecture, but I saw nothing that gave me any clue that the situation was as it was. Yes, the MAC address is shown in the router status screen, and had I correlated the first 3 hex numbers to a manufacturer, that might would have revealed it (had I recognized that the mfg was the one for the NIC in the computer). But nothing clicked in my mind to do that--since he and I are on the same ISP, and mine does not work that way.

Excuse-making I guess--and I did say FORMER CCNA <grin>. Actually, I retired four years ago and will admit I am stale (understatement).

 

[Pepper]

Then perhaps you should research Motorola Canopy Subscriber Modules because that's what we use. The radio transceiver is built into the antenna that we mount on the house, and we do NOT use a modem. We run a CAT5 cable from that subscriber module to the customer's computer or router, with a power supply adapter inserted inline...just like I said we did.

Whatever it is, if it's plugged into the customer's Ethernet device, that means it has its own MAC address which would be infinitely easier to use for "delinquent disconnect" and "billing" purposes than the MAC of the customers equipment which they have to contact you any time they change.

 

[iwc5893]

Whatever it is, if it's plugged into the customer's Ethernet device, that means it has its own MAC address which would be infinitely easier to use for "delinquent disconnect" and "billing" purposes than the MAC of the customers equipment which they have to contact you any time they change.

Not true. The Canopy radios act as a pass through device, and their MAC address does NOT show up on on the network. The customer's MAC address is what shows up in the bridge table, and is what goes out on the network...so that is what must be used for the delinquent disconnect and billing purposes.

Our billing software, which is one of the more popular billing software programs for WISPs, is what requires the MAC address for those purposes. I agree, it is a huge PITA sometimes, but it is what it is.

 

[Pepper]

Ah, so it's just a proprietary ethernet<->radio<->ethernet link, I guess the router would see the MAC of what's on the other side also then. In that case ignore my ignorant comment.