<klai@klcconsulting.net> wrote ...
> Many new network adapters on VISTA fail to support
> NDISReadNetworkAddress function.
> This is the function that allows software configurable MAC Address.
> Although the network adapters received "Certified for Windows VISTA"
> logo, they fail to support this function.
The function call NDISReadNetworkAddress() is supported and works, on Vista
and XP and in NDIS 6.0 and 5.1. However, there's no guarantee calling this
function will actually change the MAC address which a hardware device uses
to send frames. As the MSDN doc describes:
http://msdn.microsoft.com/en-us/library/bb648482.aspx
<quote>
Note that NDIS does not validate the value at NetworkAddress. NDIS does
not guarantee that this value is a valid address, that the value has the
proper length, or even that the value is a network address. The caller of
NdisReadNetworkAddress must therefore not make any assumptions about this
value and must itself validate the value. If the caller determines that the
value is out of bounds, it should not use the value; instead, it should use
the permanent medium access control (MAC) address or a default address.
</quote>
For the NDISReadNetworkAddress() call to install a Locally Adminstered
Address, there are 2 prerequisites:
- the hardware device must suport the use of locally adminstered addresses;
and
- the driver installation must create a Windows registry value at the
correct location.
Locally administered addresses ("LAA") are a common feature in network
adapters; but they are not generally required by the IEEE 802 Standards
(they are required for 802.5 devices; ie, Token Ring cards; elsewhere,
optional).
If a vendor does not implement an LAA facility in their network adapter
hardware, then there is no way to install or spoof a MAC address, you must
use the OUI address (the "burnt-in address"). It would be extremely
difficult for any operating system to override this (at least, while
conforming to IEEE standards; a malicious attack may be able to fudge
something).
For more background information about the IEEE 802 Standards, see here:
http://standards.ieee.org/getieee802/
> your input if you develop network adapter drivers. Is
> NDISReadNetworkAddress function one of Microsoft requirements for the
> network adapter to get "Certified for Windows VISTA" logo?
The requirements for Windows Logo certification are well-documented by
Microsoft. You can find details at Microsoft's device driver website
(
http://www.microsoft.com/whdc):
Windows Logo Program: Overview
http://www.microsoft.com/whdc/winlogo
Certified for Vista Requirements
http://download.microsoft.com/downlo...Spec%201.1.doc
LAAs were originally designed to accomodate specific addressing schemes in
closed, corporate networks - nainly for legacy Xerox and IBM equipment. Now
that most devices participate in standard LANs and the wide-open Internet,
there's less need for LAAs; and some folks argue that LAAs can be a vector
for malicious attacks eg spoofing. So LAAs are somewhat deprecated.
Hope it helps (and, apologies to other readers for the massive
cross-posting)
Andrew
(member, IEEE Standards Association)
--
amclar at optusnet dot com dot au
Linear Mode
