What's new

WAN MAC address random changes

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

aspen63

Regular Contributor
My ISP uses MAC address as login credentials. The problem is my AC66U running latest version of .43 fork changes its address after resets or power cycles. I noticed the same problem on previous Merlin builds as well. I couldn't find any setting related to this. Does anyone experience the same problem?
 
My ISP also uses the same method to assign "fixed DHCP address" and I never had any issues with any of the Merlin builds.

I'm also using an AC66U and Merlin 51 with stock MAC address (no MAC address substitution)


Sent using Tapatalk
 
The only way that could happen would be if you're doing something odd with MAC address cloning. Check the setting at WAN > Internet Connection > Special Requirement from ISP > MAC Address
 
I bet your ISP is just seeing a lot of DHCP queries......make sure that 'DHCP query frequency' is set to Normal mode on the same page that Colin referenced.
 
Thanks for all your replies! I'll try changing DHCP query freq to Normal (currently it's in Aggressive mode if I remember correctly). However it seems strange that this setting has something to do with changing MAC address. May be there's some other option out there that forces the router to change its MAC address upon every reboot?
 
Thanks for all your replies! I'll try changing DHCP query freq to Normal (currently it's in Aggressive mode if I remember correctly). However it seems strange that this setting has something to do with changing MAC address. May be there's some other option out there that forces the router to change its MAC address upon every reboot?
It's not possible for the router to change it's address unless you installed a script to do so.
 
Believe me or not, I'm not running any scripts. Right now I toggled Internet Connection switch to and fro and WAN MAC address changed. I used to use MAC Clone button before and it gives different addresses at times. I'm in no way an expert in network technologies so I have no idea what it means. May be the whole problem has something to do with my using powerline adapters between the router and provider's ethernet cable. The problem is clearly here and cannot be ignored.
 
May be the whole problem has something to do with my using powerline adapters between the router and provider's ethernet cable.
That sounds likely. Do you have any other devices connected to the powerline network other than the router and the modem?

[I presume the "provider's ethernet cable" is connected to a modem?]
 
That sounds likely. Do you have any other devices connected to the powerline network other than the router and the modem?

[I presume the "provider's ethernet cable" is connected to a modem?]
No, I don't have other devices connected to powerline network. I have two powerline adapters that serve as the "last mile" to the router. In my neighbourhood it's not common to have cable modems so my network layout is: provider's ethernet cable - powerline adapter - powerline adapter - router. Provider uses subscriber's MAC address as login so that's the problem.
 
No, I don't have other devices connected to powerline network. I have two powerline adapters that serve as the "last mile" to the router. In my neighbourhood it's not common to have cable modems so my network layout is: provider's ethernet cable - powerline adapter - powerline adapter - router. Provider uses subscriber's MAC address as login so that's the problem.
Very strange.

If you haven't done so already, change the powerline adapters' network name from the default (HomePlugAV) to something else. Enable encryption if that's an option. A neighbour might have powerline adapters that are connecting to your network.

Where are you reading the new MAC address from after it changes? Can you make a list of all the MAC addresses over a period of time so we can a) see how many different addresses there are, and b) identify the manufacturer of these devices.

What is the make and model of your powerline adapters?
 
Very strange indeed. I read address from WAN page in Advanced Settings (where the MAC Clone button resides).
Adapters I use are TP-LINK TL-PA6010(KIT).
 
Very strange indeed. I read address from WAN page in Advanced Settings (where the MAC Clone button resides).
When you go to WAN > Internet Connection are you saying that "MAC Address" already has a value in it? Or does it only appear when you press the "MAC Clone" button?

Is the MAC Address the same as your PC's network adapter?

I'd still recommend that you do the other things I mentioned in my previous post.
 
Very strange indeed. I read address from WAN page in Advanced Settings (where the MAC Clone button resides).
Adapters I use are TP-LINK TL-PA6010(KIT).

you're probably hitting what this guy is hitting:

http://www.snbforums.com/threads/rt-n66u-strange-cloned-mac-address-presented-to-wan.13503/
http://forums.comcast.com/t5/Home-N...ned-MAC-address-presented-to-WAN/td-p/1902095

you might want to put the router's actual WAN MAC in that field just to force it not to randomly pick a device's MAC off your LAN, while no one really know why it's happening.
 
Did you check the mac addresses of your powerline adapters against what your are seeing? The powerline adapters are essentially a private lan and each has it's own mac (on a label on the adapter). This may be a race as to who is responding to the dhcp sequence first, either of the powerline adapters or the router. I don't believe the adapters were envisioned for this application.
 
Did you check the mac addresses of your powerline adapters against what your are seeing? The powerline adapters are essentially a private lan and each has it's own mac (on a label on the adapter).
As I understand it powerline adapters do not use IEEE 802.x (Ethernet) so their MAC address is not an Ethernet MAC (http://en.wikipedia.org/wiki/IEEE_1901#Description); unless they have a secondary function such as a wireless access point, which is why I asked for the model number.
 
Last edited:
When you go to WAN > Internet Connection are you saying that "MAC Address" already has a value in it? Or does it only appear when you press the "MAC Clone" button?

Is the MAC Address the same as your PC's network adapter?

I'd still recommend that you do the other things I mentioned in my previous post.
Yes, it already has value that changes at times. I use iMac 5K as a desktop machine. You mean it's Ethernet adapter's MAC address? I'll have a look and do what you advise when I have opportunity. By the way I also have Synology NAS attached to the router by the twisted pair as well. Just curious how could the router decide which device's MAC to use in this case.
 
Yes, it already has value that changes at times. I use iMac 5K as a desktop machine. You mean it's Ethernet adapter's MAC address? I'll have a look and do what you advise when I have opportunity. By the way I also have Synology NAS attached to the router by the twisted pair as well. Just curious how could the router decide which device's MAC to use in this case.
It does sound like the problem that ChikkSpot linked to. You should be able to clear the MAC Address field, hit Apply and for it to always remain empty. If after doing that it is still putting a value in there then I'd guess that one of the NVRAM variables is corrupted.

The easiest solution would seem to be the one in ChikkSpot's linked post, i.e. find out what your real WAN MAC address is and put that in the cloned MAC address field.
 

Similar threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top