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How to change the router's MAC address

Magister76
Tutor

How to change the router's MAC address

Hello, I want to change the MAC address for my Netgear Nighthawk router.  I do not see any option for this in the router's configuration menu.

 

I know that this is possible with other Netgear routers.  Would anyone please tell me how to do this?  Thank you.

Model: C7000|Nighthawk - AC1900 WiFi Cable Modem Router
Message 1 of 15

Accepted Solutions
TheEther
Guru

Re: How to change the router's MAC address

If you like Nighthawks, then get one without a modem (link).

 

Any DOCSIS 3 modem should be fine but if you want to insure that you receive firmware updates from Comcast, then you may want to choose one that is supported by them (link).

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Message 15 of 15

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TheEther
Guru

Re: How to change the router's MAC address

You have a cable modem router.  You can't change the MAC address because your Internet service is tied to it.

Message 2 of 15
Magister76
Tutor

Re: How to change the router's MAC address

I don't understand what you mean, since I can change my MAC address by purchasing a new cable modem router, and then I would report my new MAC address to my ISP and my Internet service would be just fine.

 

So, does the Nighthawk allow me to change my MAC address? And if not, why?

Message 3 of 15
TheEther
Guru

Re: How to change the router's MAC address

The MAC address is so integral to cable Internet service that it doesn't really make sense for it to be changeable.  You could effectively steal someone's service with that capability.

Message 4 of 15
VE6CGX
Master

Re: How to change the router's MAC address

Any piece of NIC , WiFi card or router has unique MAC address embedded in the unit when they were made. It is like your SSN, Do you think

there would be two identical SSN or two identical plate no. for two different cars?  Another word it is like finger print. But... you can change it

getting into brain of the hardware by hacking. But I don't see the purpose. In the case of router you have two MAC one for wired, one for wireless. May I ask why you want to change it? Or I think you are talking about MAC cloning when you set u[p the router? If you play with MAC cloning

you can lose I'net connection.

Message 5 of 15
Magister76
Tutor

Re: How to change the router's MAC address

Yes, I think I'm refering to MAC cloning. I guess some people also use the word "spoofing". The purpose is to get my ISP to issue me a new DHCP IP address.
Message 6 of 15
VE6CGX
Master

Re: How to change the router's MAC address

What is the purpose of wamnting different address?  What did you try so far?

Message 7 of 15
Magister76
Tutor

Re: How to change the router's MAC address

I have my reason and I don't really feel like it matters for this discussion. I know how DHCP works and the ISP leases an IP that is tied to the MAC address. If I call them they won't change the IP. That's their policy but technically they are easily capable of doing it. I've tried rebooting the router/modem but obviously the IP doesn't change because the MAC is the same and it picks up the same lease from the ISP. So is there a way to do what I want to do, short of buying a whole new router/modem?
Message 8 of 15
TheEther
Guru

Re: How to change the router's MAC address

The short answer is, there is no way to change the MAC address without buying a separate modem and router.

 

What you are failing to understand is that this goes beyond tying an IP address to a MAC address.  When it comes to coax cable Internet service, the ISP ties your Internet subscription to your modem's MAC address.  As in, "Magister76 is a paying customer with MAC address XYZ".  If you were, somehow, able to change your modem's MAC address, your ISP would no longer recognize your modem as being associated with you.  You would be perceived as either a non-customer (e.g. a guy moves into a house and hooks up a modem without subscribing for service) or as another customer with the same MAC address.  Do you see the havoc that would ensue if customers chould change the MAC addresses on their modems?

 

You correctly point out that an IP address is tied to a MAC address for DHCP.  It's not too hard to guess that you want to change your IP address because you are being DoS attacked or you are trying to hide your identity.  Changing the MAC address is often useful to force a change in IP address.  The problem is that a combination router/modem only has one Internet-facing MAC address.  In this respect, a modem/router is just like a pure modem in that its MAC address cannot be changed for the reason I gave previously.

 

You can try shutting off your modem/router for at least one full day in the hopes that the ISP's DHCP server will flush its IP to MAC assignment.  If that fails, then you will have to replace your modem/router.  If you expect to change your IP address multiple times, then I suggest you buy a separate modem and router.  This will decouple the customer-to-MAC and IP-to-MAC association (i.e. your modem's MAC identifies you as a customer and your router's MAC is used for IP adddress assignments).  Then you can use the router's MAC spoofing/cloning feature to force IP address changes.

Message 9 of 15
Magister76
Tutor

Re: How to change the router's MAC address

TheEther, thanks for the explanation. I appreciate that. Just to verify what you are saying...I think I understand now that since my Nighthawk is an all-in-one cable modem and router device, there is only one WAN facing MAC address and that, therefore, the software hasn't been programmed to allow MAC cloning since it would be disruptive to the ISP. Also, I think I understand from what you said, if I had a cable modem and a router as two separate devices, the router would have it's own MAC and the cable modem would also have it's own MAC. And, therefore, the feature to allow MAC spoofing would be enabled for the router since doing so wouldn't interfere with the cable modem's MAC. Now I have another question (assuming what I said above is correct)...if I did go ahead and get a separate router and a separate cable modem, would cloning the MAC of the router work to get a new IP lease even though the MAC of the cable modem would stay the same? I'm not familiar with how DHCP operates with ISP's and their cable modems, but it seems to me that, regardless of the router's MAC address, if the MAC of the cable modem does not change then the leased IP would stay the same. Thoughts?
Message 10 of 15
VE6CGX
Master

Re: How to change the router's MAC address

Only once I managed to do that. Complaining about my cable signal quality/speed non-stop to my ISP. Finally they did something, next thing I know I was given different address.

Message 11 of 15
VE6CGX
Master

Re: How to change the router's MAC address

Checked 3rd party f/w on this?

Message 12 of 15
TheEther
Guru

Re: How to change the router's MAC address


@Magister76 wrote:
TheEther, thanks for the explanation. I appreciate that. Just to verify what you are saying...I think I understand now that since my Nighthawk is an all-in-one cable modem and router device, there is only one WAN facing MAC address and that, therefore, the software hasn't been programmed to allow MAC cloning since it would be disruptive to the ISP. Also, I think I understand from what you said, if I had a cable modem and a router as two separate devices, the router would have it's own MAC and the cable modem would also have it's own MAC. And, therefore, the feature to allow MAC spoofing would be enabled for the router since doing so wouldn't interfere with the cable modem's MAC.

Yes, this is correct.

Now I have another question (assuming what I said above is correct)...if I did go ahead and get a separate router and a separate cable modem, would cloning the MAC of the router work to get a new IP lease even though the MAC of the cable modem would stay the same? I'm not familiar with how DHCP operates with ISP's and their cable modems, but it seems to me that, regardless of the router's MAC address, if the MAC of the cable modem does not change then the leased IP would stay the same. Thoughts?

A pure modem is a layer 2 networking device.  It won't request an IP address from your ISP.  Only your router will request an IP address, so MAC cloning will work.

 

@VE6CGX wrote:
Checked 3rd party f/w on this?

3rd party firmware is virtually non-existent for router/modems.  You can probably count on one hand the number of models with 3rd party firmware.  On this list, for example, I think the DGND3700 is the only one.

Message 13 of 15
Magister76
Tutor

Re: How to change the router's MAC address


@TheEther wrote:



A pure modem is a layer 2 networking device.  It won't request an IP address from your ISP.  Only your router will request an IP address, so MAC cloning will work.

That makes perfect sense. Thanks again. Now I think I want to buy a separate router and cable modem. I really like the features of the Nighthawk. Would you recommend a router that is comparable to the Nighthawk? Especially one that has MAC cloning capability. And, as far as the cable modem goes, I guess any DOCSIS 3 would be fine?
Message 14 of 15
TheEther
Guru

Re: How to change the router's MAC address

If you like Nighthawks, then get one without a modem (link).

 

Any DOCSIS 3 modem should be fine but if you want to insure that you receive firmware updates from Comcast, then you may want to choose one that is supported by them (link).

Message 15 of 15
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