Solved MAC Address

[HammerHead]

Something I am not familiar with.
I recently had to reset my router.When I did everything took off just fine. Really wasn't much of a problem. I have two rigs tied with ethernet. Sometime later My WOL wouldn't operate. I found a MAC address was different than what had been working.Evidently the reset set a new MAC. No problem I just reentered the Mac in to the WOL app and everything is back to normal. What I am asking is --- If I set a network address in the config for my adapter will it accept that MAC on another reset? It previously did not have an entry (blank)

View attachment 199090

 

[richnrockville]

Hammerhead, My first thought is that it won't survive a reboot as the mac address is burned into a chip on the adapter. When reboot, it reads all the spec's from your network adapter.

Rich

 

[Qdos]

The only way you can change MAC details is by reflashing the device, and I don't mean a firmware upgrade, I'm talking of a very specific type of reflash that is rarely performed.

That simply cannot happen by accident

 

[HammerHead]

Okey Dokey

That leaves me to find out what really happened. I don't have a clue right now. Everything is working fine. Even with the addresses I entered into the adapter settings. I'll figure it out later I guess because it is likely to happen again.

Rich it survied a reboot. I didn't change the mac address any where except in my software and it now matches what ipconfig returns.

If the mac is burned into the hardware that means each and every adapter manufactured by any one is unique unto it self? I wonder if I unknownly downloaded a firmware up date to my router.

 

[Qdos]

Even a router upgrade wouldn't alter the adapters MAC address...

 

[richnrockville]

That leaves me to find out what really happened. I don't have a clue right now. Everything is working fine. Even with the addresses I entered into the adapter settings. I'll figure it out later I guess because it is likely to happen again.

Rich it survied a reboot. I didn't change the mac address any where except in my software and it now matches what ipconfig returns.

If the mac is burned into the hardware that means each and every adapter manufactured by any one is unique unto it self? I wonder if I unknownly downloaded a firmware up date to my router.

A soft boot might keep the MAC but something tells me that a power off full reboot might reset the MAC back to the one on the chip on the board.

And yes, Each and every adapter that is manufacturered has its own address. Otherwise the world of IP's would be in a termoil. If you looked at the MAC address, you can determine who manufactured it. In fact a long time ago I believe one of the manufacturers mistakenly duplicated MAC address's and had a rough go at it.
It is not a good idea to change the MAC address on cards as it could conflict with another one in the world.
Rich

 

[Qdos]

It's OK to have the same MAC address as someone else on an adapter, the only time it causes a problem is when matching MAC numbers are used on the same subnet behind the same router, when it will result in an unresolvable IP conflict. However the odds of this happening are millions to one against.

I had a problem with a motherboard where the BIOS chip was bricked, and I had to fit a new one. Everything was fine except the MAC addresses for my NIC adapter and my 1394 Firewire adapter weren't programmable into the new BIOS chip without special tools from the motherboard manufacturer.

Reflashing them was based on providing the board serial number to the manufacturer, who in turn gave me a range of MAC addresses which would work for both chips, and two different bootable ISO files to enable the reprogramming.

 

[HammerHead]

OK

Qdos
Ok I understand now. Good job on your board. Mybe what I had was a software glitch.

 

[HammerHead]

Power

Rich it was turned off over night (via case power button). Is that what you mean? I would call that "hard" as opposed to reboot with software or reset button.

 

[richnrockville]

Rich it was turned off over night (via case power button). Is that what you mean? I would call that "hard" as opposed to reboot with software or reset button.

Yes, that's what I meant.

Based on my understanding of ethernet adapter boards (which is not a lot) I was under the impression that the only way to permanently change the address was by replacement of the rom on the board. But maybe the software driver allows you to change the rom. Wierd and I would have bet money (which I evidently would have lost) that it was not possible without a rom change or burner..

Good luck

Rich

 

[HammerHead]

No Real Change

The only thing I changed was the MAC address in my WOL app. I thought because it was incorrect that the adapter had changed. I don't think the adapter changed. I now think the WOL app got borked somehow. That sceneario jibes best with what you guys are telling me. Both rigs are working fine after being off all night. I did ipconfig and saved it to a txt file. Next time I'll have a place to check addresses and I won't be so confused. Thanks for all the help.

 

[HammerHead]

Change A Mac

No not a Big Mac

You might like to read this.

How to Change a MAC Address