MAC address

I changed the IP address of my desktop to 192.168.0.2 and all my diagnostic
tools are telling me that my MAC address has changed to 19-02-16-00-02 from
00-0C-76-19-31-10. How can this be? Its a VIA Rhine II Fast Ethernet
Adapter. I thought the MAC was burned in. It cant be right, can it?

Hi,

Are you sure that you change the IP address and not the mac address? Some
network cards allow you to configure the mac address manually.

Thanks,
Marc Reynolds
Microsoft Technical Support

This posting is provided "AS IS" with no warranties, and confers no rights.

Thank you for your reply. The VIA Rhine II is built into the motherboard
(MSI MS-6738, VIA KM266 chipset). If there is some way to change the MAC
address on this board I would be glad to know about it as my computers can
no longer see each other.
"Marc Reynolds [MSFT]" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
>
> Are you sure that you change the IP address and not the mac address? Some
> network cards allow you to configure the mac address manually.
>
> Thanks,
> Marc Reynolds
> Microsoft Technical Support
>
> This posting is provided "AS IS" with no warranties, and confers no
rights.
>

(E-Mail Removed) (Marc Reynolds [MSFT]) wrote in message news:<(E-Mail Removed)>...
> Hi,
>
> Are you sure that you change the IP address and not the mac address? Some
> network cards allow you to configure the mac address manually.

I didn't realise that one could change a MAC address, I thought that
was part of the hardware settings.

I've recently been getting two network cards reporting a different
Access Point MAC address after I changed the security settings.

Geoff Lane

The MAC address is burnt into ROM at the manufacturer and can't be changed.
It's a unique HEX address and no two NIC's in this world have the same MAC
address.
Bernie

"Geoff Lane" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> (E-Mail Removed) (Marc Reynolds [MSFT]) wrote in message
news:<(E-Mail Removed)>...
> > Hi,
> >
> > Are you sure that you change the IP address and not the mac address?
Some
> > network cards allow you to configure the mac address manually.
>
> I didn't realise that one could change a MAC address, I thought that
> was part of the hardware settings.
>
> I've recently been getting two network cards reporting a different
> Access Point MAC address after I changed the security settings.
>
> Geoff Lane

"Bernie" <(E-Mail Removed)> wrote in
news:OM5#(E-Mail Removed):

> The MAC address is burnt into ROM at the manufacturer and can't be
> changed. It's a unique HEX address and no two NIC's in this world have
> the same MAC address.
> Bernie
>
Do a google search for "change mac address" and you'll see how to.

On Tue, 16 Sep 2003 21:13:08 -0500, "Bernie" <(E-Mail Removed)>
wrote:

>> I didn't realise that one could change a MAC address, I thought that
>> was part of the hardware settings.
>>
>> I've recently been getting two network cards reporting a different
>> Access Point MAC address after I changed the security settings.

>The MAC address is burnt into ROM at the manufacturer and can't be changed.
>It's a unique HEX address and no two NIC's in this world have the same MAC
>address.
>Bernie

That's what I thought but Marc Reynolds queried an earlier post asking
if it was the MAC address that was changed rather than the IP address.

I've been getting some wierd MAC addresses reported from my various
Netgear products.

Geoff Lane

Geoff Lane wrote:

> On Tue, 16 Sep 2003 21:13:08 -0500, "Bernie" <(E-Mail Removed)>
> wrote:
>
>
>>>I didn't realise that one could change a MAC address, I thought that
>>>was part of the hardware settings.
>>>
>>>I've recently been getting two network cards reporting a different
>>>Access Point MAC address after I changed the security settings.
>
>
>>The MAC address is burnt into ROM at the manufacturer and can't be changed.
>>It's a unique HEX address and no two NIC's in this world have the same MAC
>>address.
>>Bernie
>
>
> That's what I thought but Marc Reynolds queried an earlier post asking
> if it was the MAC address that was changed rather than the IP address.
>
> I've been getting some wierd MAC addresses reported from my various
> Netgear products.
>
> Geoff Lane
>
I believe some cards allow changes to their MAC address. That makes
it possible to transparently replace one that fails by setting the
MAC of the new one to that of the failed one.

"CJT" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Geoff Lane wrote:
>
> > On Tue, 16 Sep 2003 21:13:08 -0500, "Bernie" <(E-Mail Removed)>
> > wrote:
> >
> >
> >>>I didn't realise that one could change a MAC address, I thought that
> >>>was part of the hardware settings.
> >>>
> >>>I've recently been getting two network cards reporting a different
> >>>Access Point MAC address after I changed the security settings.
> >
> >
> >>The MAC address is burnt into ROM at the manufacturer and can't be
changed.
> >>It's a unique HEX address and no two NIC's in this world have the same
MAC
> >>address.
> >>Bernie
> >
> >
> > That's what I thought but Marc Reynolds queried an earlier post asking
> > if it was the MAC address that was changed rather than the IP address.
> >
> > I've been getting some wierd MAC addresses reported from my various
> > Netgear products.
> >
> > Geoff Lane
> >
> I believe some cards allow changes to their MAC address. That makes
> it possible to transparently replace one that fails by setting the
> MAC of the new one to that of the failed one.
>
I wasn't aware of this either, however it does seem to be targeted towards
server operating systems and servers from what I've read and not Win98. I
can see why someone might wish to change it on a server but not an end user
system. Not that this would matter much as long as an organization had a
robust set of configurable routers and switches. If your hardware has no
com or serial ports to telnet into and configure I imagine you'd might need
to use this more than others would.

Personally I'd kind of view it as a bit of a security problem if someone
were able to change their MAC address at will. I could see folks changing
their MAC then when using DHCP release and renew then doing whatever they
wish and then changing it back again especially if the switch is accessible
to anyone. They'd have a different MAC, IP address and switch port to do
whatever nefarious activity they wish and remain undetectable.

No way in hell would I purchase systems with NIC cards for end users that
allowed this.
Bernie

On Wed, 17 Sep 2003 21:02:12 GMT, CJT <(E-Mail Removed)> wrote:


>>>The MAC address is burnt into ROM at the manufacturer and can't be changed.

>> That's what I thought but Marc Reynolds queried an earlier post asking
>> if it was the MAC address that was changed rather than the IP address.
>>
>> I've been getting some wierd MAC addresses reported from my various
>> Netgear products.

>I believe some cards allow changes to their MAC address. That makes
>it possible to transparently replace one that fails by setting the
>MAC of the new one to that of the failed one.

Strangely, with my Netgear AP and PC card the PC card would report the
correct AP MAC address unless I had WEP enabled and shared key, the
last 3 pairs of HEX digits would then change.

I would get the same changed AP address on my handheld if I enabled
WEP.

Netgear say this is a security feature, not sure how.

Geoff Lane
Welwyn Hatfield Computer Club - Hertfordshire, UK
www.whcc.co.uk - Online facilities for non locals