Wireless mac address anomoly

I recently purchased a D-Link 624 RevC router and a D-Link DWL-G650
wireless PCMCIA card for my laptop. I've got a mac address problem
that's throwing me for a loop.

When I do a IPCONFIG /ALL on the laptop, I get one MAC address.
However, there is a totally different MAC address printed on the card
itself. Now, when I set up a static DHCP entry in the router, I have
to use the IPCONFIG MAC address. When I set up filtering to only
allow certain MAC addresses to access the network, I have to use the
one printed on the card.

I'm new to wireless stuff and don't know if this is the norm. Can
someone help me understand this? Is this just a screwed up card by
D-Link?

Do you by any chance also have the laptop's Ethernet connected to the
router? If you do, are you confusing the Ethernet and the wifi MAC
addresses?

Unless something is reassiging the client adapter's MAC address - which
normally can only happen if you do something to make it happen, and even
then is not possible with all cards - the MAC it uses is the one that's
burned in, which should be the one written on the label.


"tommy" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> I recently purchased a D-Link 624 RevC router and a D-Link DWL-G650
> wireless PCMCIA card for my laptop. I've got a mac address problem
> that's throwing me for a loop.
>
> When I do a IPCONFIG /ALL on the laptop, I get one MAC address.
> However, there is a totally different MAC address printed on the card
> itself. Now, when I set up a static DHCP entry in the router, I have
> to use the IPCONFIG MAC address. When I set up filtering to only
> allow certain MAC addresses to access the network, I have to use the
> one printed on the card.
>
> I'm new to wireless stuff and don't know if this is the norm. Can
> someone help me understand this? Is this just a screwed up card by
> D-Link?

The laptop does not have a built in Ethernet port. The only network
adapters it has is dialup networking (which was not on-line at the
time) and the wireless nic.

Okay, you say that you need to use the ipconfig-listed MAC address to get a
static DHCP address to assign, but MAC filtering requires the advertised MAC
address, right? And that the ipconfig MAC address doesn't match the card's
advertised MAC.

The client adapter and its driver can't respond to two different MAC
addresses. At least, the probability of either being broken in such a way
that it happens is exceedingly small. There has to be some confusion here
about which device one of these two addresses is associated with. Since it
is also very unlikely that the card is burned in with a wrong address - if
you bought it from a reputable DLink retailer - I suspect something is wrong
with your interpretation of the ipconfig /all results. The fact that you
have to use the advertised MAC address to get filtering to work supports
this.

Can you post a copy of your ipconfig /all output? Also, state what your
desired static IP address is.

"tommy" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> The laptop does not have a built in Ethernet port. The only network
> adapters it has is dialup networking (which was not on-line at the
> time) and the wireless nic.

Confusion on my part is certainly a possibility.

My desired IP is what is shown below, 192.168.1.102 whenever it sees
the IPCONFIG-indicated MAC of 32-BB-09-A3-92-64.

But, what is printed on the card is MAC address 00-0D-88-55-B7-BB
which must be in the MAC address filter.

-----------------------------------------------------
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Tommy>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : tlaptop
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Network Bridge:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : MAC Bridge Miniport
Physical Address. . . . . . . . . : 32-BB-09-A3-92-64
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.102
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
Lease Obtained. . . . . . . . . . : Wednesday, February 11,
2004 7:56:46
AM
Lease Expires . . . . . . . . . . : Wednesday, February 18,
2004 7:56:46
AM

C:\Documents and Settings\Tommy>
-------------------------------------------

"tommy" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Confusion on my part is certainly a possibility.
>
> My desired IP is what is shown below, 192.168.1.102 whenever it sees
> the IPCONFIG-indicated MAC of 32-BB-09-A3-92-64.
>
> But, what is printed on the card is MAC address 00-0D-88-55-B7-BB
> which must be in the MAC address filter.

The first 6 digits - 00-0D-88 - identify the manufacturer as D-Link (you can
look this up in a database on the IEEE public web site). This has to be the
correct MAC address for your wifi client adapter.

Your ipconfig dump does not show any wifi device. It shows an Ethernet
network bridge. The fact that I see neither Ethernet nor wifi devices is
very odd. Any laptop made in the last 5 or 10 years normally has an Ethernet
on the motherboard, whether you want it or not, so the fact that you don't
seem to have one is strange. And I would expect to see a clearly-identified
wireless device entry.

The address 32-BB-09-A3-92-64 is a locally-administered MAC address. That
means it is not a burned-in address on a real device, it is an address
created dynamically by XP for the bridge, which is a pseudo-device. It's not
associated with any vendor. Did you intentionally set up a network bridge,
or did this happen as a result of the install?

You didn't say the wifi network isn't working, so I'm going to assume that
wifi is working for you, and we're just trying to explain the MAC address
anomaly.

It is possible that the G-650 is set up something like this:

The install process inserts a network bridge between the G-650 device driver
and the TCP/IP stack. This is a software bridge ordinarily used to move
layer 2 frames directly between two network devices - for example, one
Ethernet to another, or wifi <-> Ethernet. The bridge would normally
cross-connect two two hardware device drivers. Here, there is only one
device, but you could create a fake, or null, device with the
locally-administered MAC address, build the TCP/IP stack on top of that, and
then use the bridge to mediate between the virtual wifi device with the fake
MAC address, and the real wifi device. Then the local TCP/IP stack would see
only the fake device with its fake MAC address at the bottom of its stack,
and when it sends DHCP discovery packets, it would include that address in
the IP datagrams. The 802.11 frames would continue to bear the real MAC
address, so MAC filtering would require that.

I'm just speculating here, because I've never seen this. If I'm right, I
have no idea why it would be done this way. I could certainly be wrong. I
have an AG-650, which I would have thought builds a stack the same way as
your G-650, and on my XP, ipconfig /all clearly shows a wifi device with
TCP/IP sitting directly over it. Note that a bridge might also explain why
we don't see a configured wireless device - the device is displayed only if
a TCP/IP stack is configured directly over it (I verified that by
temporarily disabling all stack elements over my Ethernet device - the entry
disappeared from ipconfig /all).

>
> -----------------------------------------------------
> Microsoft Windows XP [Version 5.1.2600]
> (C) Copyright 1985-2001 Microsoft Corp.
>
> C:\Documents and Settings\Tommy>ipconfig /all
>
> Windows IP Configuration
>
> Host Name . . . . . . . . . . . . : tlaptop
> Primary Dns Suffix . . . . . . . :
> Node Type . . . . . . . . . . . . : Hybrid
> IP Routing Enabled. . . . . . . . : No
> WINS Proxy Enabled. . . . . . . . : No
>
> Ethernet adapter Network Bridge:
>
> Connection-specific DNS Suffix . :
> Description . . . . . . . . . . . : MAC Bridge Miniport
> Physical Address. . . . . . . . . : 32-BB-09-A3-92-64
> Dhcp Enabled. . . . . . . . . . . : Yes
> Autoconfiguration Enabled . . . . : Yes
> IP Address. . . . . . . . . . . . : 192.168.1.102
> Subnet Mask . . . . . . . . . . . : 255.255.255.0
> Default Gateway . . . . . . . . . : 192.168.1.1
> DHCP Server . . . . . . . . . . . : 192.168.1.1
> DNS Servers . . . . . . . . . . . : 192.168.1.1
> Lease Obtained. . . . . . . . . . : Wednesday, February 11,
> 2004 7:56:46
> AM
> Lease Expires . . . . . . . . . . : Wednesday, February 18,
> 2004 7:56:46
> AM
>
> C:\Documents and Settings\Tommy>
> -------------------------------------------

Do I need this MiniPort bridge? Is this something I can remove?
What's it's purpose?

"tommy" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Do I need this MiniPort bridge? Is this something I can remove?
> What's it's purpose?

I tried to explain a theory in the previous post. I've thought about it some
more, and the theory (as stated) doesn't quite work.

I'm still not clear about whether you can access the Internet from a
wireless device. If you can, then your wifi setup is working, and we're just
trying to explain why you have this anomaly. If you can't, then there is a
config issue that needs to be resolved.

Which is it?

Sorry I didn't mention that. I saw that in your post but was
distracted when I wrote the reply.

Yes, internet is working fine. I only want to understand the anomoly.
The bridge might have been installed when I tried to set up internet
connection sharing some months ago. I remember seeing a "bridge"
installed at the time. Since I've gotten cable modem, I abandoned the
effort. I don't know if it was installed as result of the internet
connection sharing or if it is, indeed, something that the card
installed.

Okay, sounds like the bridge is left over from the connection sharing
experiment, and not needed. You should be able to remove the bridge via the
control panel. Under control panel (default view, not "classical view"),
"Network and Internet Connections", "Network Connections", there should be a
display of network devices. You should see the bridge. Just right-click the
bridge icon and select delete.

After the bridge is removed, you should be able to see an Ethernet and a
wifi device. In fact you should see Ethernet and wifi icons in the network
device display along with the bridge - but removing the bridge should make
them show up in ipconfig /all. I'd like to know what the ipconfig /all dump
looks like when the bridge is deleted.


"tommy" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ...
> Sorry I didn't mention that. I saw that in your post but was
> distracted when I wrote the reply.
>
> Yes, internet is working fine. I only want to understand the anomoly.
> The bridge might have been installed when I tried to set up internet
> connection sharing some months ago. I remember seeing a "bridge"
> installed at the time. Since I've gotten cable modem, I abandoned the
> effort. I don't know if it was installed as result of the internet
> connection sharing or if it is, indeed, something that the card
> installed.