Chaging the hardware address of the NIC

NTDEV
1

Hello

I am developing a driver for a NIC on which the MAC(hardware) address can
be changed on the fly.

Is there a way to let the NDIS (and hence IP layer) know that whenever there
is a change in the MAC address so that IP can reconfigure its ARP table (or
send a query to find the changed MAC address)?

Thanks in advance

  • Bill

Is your PC infected? Get a FREE online computer virus scan from McAfee®
Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963

2

On Mon, 2004-06-28 at 19:33, Bill Wells wrote:

Hello

I am developing a driver for a NIC on which the MAC(hardware) address can
be changed on the fly.

Is there a way to let the NDIS (and hence IP layer) know that whenever there
is a change in the MAC address so that IP can reconfigure its ARP table (or
send a query to find the changed MAC address)?

Check out the iphlpapi (IP Helper API). You can bounce the interface
from usermode (or maybe just release/renew), if that makes sense. Maybe
also try SendArp() on your own address.

You should check this out if you haven’t already, as it is possible that
tcpip.sys figures this out automatically (don’t know for sure; I’d be
interested to hear the results if you try).

From kernel mode, I guess I’d try sending a pre-fabricated ARP reply
with the new MAC address to tcpip.sys, but I have no idea at all if that
would work. It might just result in an IP address conflict warning, but
then again, tcpip.sys might be smart enough to see the source/dest MAC
address and realize it matches the hardware address in the ARP reply.
Again, no idea if this works, but I’d be curious to know the results.

Good luck.

-sd

3

No. Disable and re-enable the device.

NDIS queries the MAC address very early, even before any protocols are
bound. It uses it in the packet filters.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Bill Wells”
To: “Windows System Software Devs Interest List”
Sent: Tuesday, June 29, 2004 4:33 AM
Subject: [ntdev] Chaging the hardware address of the NIC

> Hello
>
> I am developing a driver for a NIC on which the MAC(hardware) address can
> be changed on the fly.
>
> Is there a way to let the NDIS (and hence IP layer) know that whenever there
> is a change in the MAC address so that IP can reconfigure its ARP table (or
> send a query to find the changed MAC address)?
>
> Thanks in advance
> - Bill
>
> _________________________________________________________________
> Is your PC infected? Get a FREE online computer virus scan from McAfee?
> Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
>
>
> —
> Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
>
> You are currently subscribed to ntdev as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com