FIX for IPCONFIG failing with Unknown media status code error

On Mon, 05 Mar 2007 19:08:50 GMT, John Navas wrote in :

UPDATE: I used Lenovo Software Installer on the ThinkPad T41 to update the original Windows XP driver 6.4.16.36 (06/13/2003) to 7.2.17.101 (10/26/2004), which also works properly (Network Cable Unplugged instead of automatic Disable). Thus my working hypothesis is that this problem was introduced by Intel in Version 8 of its drivers, probably as a well-intended improvement that fell prey to the Law of Unintended Consequences.

On Mon, 05 Mar 2007 19:58:00 GMT, John Navas wrote in :

NOTES on the ThinkPad T41:

1. ThinkVantage Access Connections isn't installed, so wouldn't seem to have any bearing on the problem.
2. Intel PROSet for Windows Device Manager isn't installed, so likewise wouldn't seem to have any bearing on the problem.
3. There is no apparent option for turning off auto Disable when disconnected in Intel Version 8 drivers.

My gut instinct is that the "disabled" showing up in the Network Connections is probably a symptom of the bug in the driver rather than part of the causal chain. If you look in WMI, there are driver response code for "media status". My guess is that the problem is related either to power management or to link negotiation of some sort. I've noticed that it's almost exactly 40 seconds after unplugging the cable that the problem arises - in the 40 second window, it will properly report that the media is disconnected, but once that 40 second window is up you start to get the ipconfig crashes. Win32_NetworkAdapter will report 7 for media status (i.e. disconnected media) in that 40 second window, but starts reporting 0 (i.e. driver disabled) once the driver starts outputing bogus values, even though as we well know the driver isn't disabled.

I believe Win32_NetworkAdapter (in root\\cimv2) is built on top of the more primitive stuff in root\\wmi (i.e. all the MSNdis_* classes), and all of that talks to the drivers (as far as I can tell). My guess is that when Win32_NetworkAdapter gets an illegal value, it simply reports that the device is disabled (even if the driver isn't), because it has to do something (and it's better to decide the device is disabled than to crash).

I've tried messing with the GUI power management as well as "AutoPowerSaveModeEnabled", "SavePowerNowEnabled", and "ReduceSpeedOnPowerDown" in the registry. I've tried messing with the WaitForLink stuff as well. All to no avail.

In the end I ended up modifying my network adapter management code to disable the interface (you can do it using devcon and code like devcon.exe disable "@PCI\\VEN_8086&DEV_101E&SUBSYS_05491014&*") whenever it's not plugged in and then to turn it on for 10 seconds once a minute to check to see if it got plugged in. Annoying as all get out (since the user sees the notification icons flashing), but I didn't write the driver!

--Toby Ovod-Everett

On 27 Mar 2007 17:15:28 -0700, snipped-for-privacy@ovod-everett.org wrote in :

Agreed, although I suspect Intel would call it a "feature" rather than a bug. ;)

Power management settings have no effect on the problem. I think it's intentional, to eliminate the Windows "cable disconnected" popup (that can be annoying or confusing, depending on your level of expertise).

Just because the power management settings have no effect on the problem doesn't mean it's not power management. The driver could be ignoring the settings! Also, the proper behavior shows up in the PRO/

100 drivers (VM, VE) from the same driver set, so if they did do it deliberately, they didn't do it across both drivers (although that wouldn't be surprising). That said, if it was intentional, they picked a strange way to do it. Finally, the 40 second timeout is one of the things that makes me think it might be a power management deal

- if it were to eliminate the popup, don't you think they'd do it immediately, rather than waiting 40 seconds. Whereas if there's a hardware setting to automatically reduce power consumption by the port whenever it's been disconnected for 40 seconds or more, and the driver is somehow reporting that, then that would be an explanation.

When I get a chance, I'll investigate and see if the same behavior is seen on our Dell GX260's, which have "Intel(R) PRO/1000 MT Network Connection" (versus the "Intel(R) PRO/1000 MT Mobile Connection" on the T41). Unfortunately, all of our other Gigabit notebooks are using the Broadcom chipset, so I can't use them for comparison.

--Toby Ovod-Everett

I verified last night that the "Intel(R) PRO/1000 MT Network Connection" driver (same version of the driver file - 8.7.9.0) on a Dell GX260 (which is a desktop as opposed to a notebook) works fine (i.e. two minutes after unplugging the network cable, ipconfig was still reporting "Media disconnected"). So whatever the problem is, it's not present on all PRO/1000 MT hardware, but appears to be linked to the Mobile variant of it for the notebooks.

Which lends some weight to my hunch that it may be related to some form of power saving functionality (whether or not the behavior is configurable via the power management settings), since power saving functionality isn't as critical in a desktop system.

--Toby Ovod-Everett

On 4 Apr 2007 17:32:44 -0700, snipped-for-privacy@ovod-everett.org wrote in :

Thanks for the info. My ThinkPad T41 is currently out for repair by Lenovo. I'll do some more investigation when I get it back.

On 4 Apr 2007 17:32:44 -0700, snipped-for-privacy@ovod-everett.org wrote in :

So it's apparently just MT _Mobile_ that's affected. Interesting.

I don't think so. I think something else is going on.

As I promised (long ago), I've now run more tests on my ThinkPad T41, using Microsoft Update to install Intel PRO/1000 MT Mobile wired network adapter driver 8.9.1.0 (03/25/2007), which is later than the version from Lenovo that I tested earlier. With this driver, the Unknown media status code error returns, and turning off power management in the driver again has no effect on the problem.

Interestingly, this latest driver does not disable the network adapter in Network Connections -- when not in use, it stays at Network cable unplugged -- so that theory of mine wasn't valid. (This change suggests that Intel might have responded to my initial report but failed to fix the problem.)

When I rolled the driver back to 7.2.17.101 (10/26/2004), the Unknown media status code error again went away. Hence this remains the only known work-around to the problem. For what its worth, I carefully compared all settings (including power state) of this driver to the v8 driver and could find no differences.