und somit gibts kein Netzwerk mehr.

Nachteil - der Rechner ist in der Netzwerkumgebung nicht mehr zu sehen und kann auch auf seine eigenen (quasi lokalen) Ressource nicht mehr zugreifen. Das ist unter Umständen aber unglücklich, da bestimmte Applikationen einen Sharepoint brauchen. Z.B Netinstall.

Das muß nicht sein; Lösung :

Use Registry Editor (Regedt32.exe) to view the following key in the
registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\P arameters

Add the following registry value:

Value Name: DisableDHCPMediaSense
Data Type: REG_DWORD -Boolean
Value Data Range: 0, 1 (False, True) Default: 0 (False)

Klappt wunderbar. Zu beachten ist aber: Auch nach dem Eintrag funktioniert das Browsen nicht. Zugriff auf die Ressource nur via UNC-Pfad. Es funktioniert nur an reinen RJ45 - Adaptern. Also nicht BNC.

Im Anhang das Originale Topic der Technet März 2001:
How to Disable Media Sense for TCP/IP in Windows 2000 [Q239924]

PSS ID Number: Q239924
Article last modified on 07-27-2000

WINDOWS:2000
============================================================ ==========
-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Datacenter Server
- Microsoft Windows 2000 Professional
- Microsoft Windows 2000 Server
-------------------------------------------------------------------------------

SUMMARY
=======

Windows 2000 contains the "Media Sensing" feature. You may use this feature on a
Windows 2000-based computer using Transmission Control Protocol/Internet
Protocol (TCP/IP) to detect whether or not your network media is in a "link
state". A "link state" is defined as the physical media connecting or inserting
itself on the network. For example, assuming a 10bt or 100bt physical media,
Ethernet network adapters and hubs typically have a "link" light to indicate the
current connection status. This is the same condition in which Windows 2000 can
detect a link. Whenever Windows 2000 detects a "down" state on the media, it
removes the bound protocols from that adapter until it is detected as "up"
again. There may be situations where you may not want your network adapter to
detect this state, and you can configure this by editing the registry.

NOTE: 10b2 or coaxial (RG-58) Ethernet cable is not a connection-based media.
Because of this, Windows 2000 does not attempt to detect a "connect" state if
this type of cabling is used.

MORE INFORMATION
================

WARNING: Using Registry Editor incorrectly can cause serious problems that may
require you to reinstall your operating system. Microsoft cannot guarantee that
problems resulting from the incorrect use of Registry Editor can be solved. Use
Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and
Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete
Information in the Registry" and "Edit Registry Data" Help topics in
Regedt32.exe. Note that you should back up the registry before you edit it. If
you are running Windows NT or Windows 2000, you should also update your
Emergency Repair Disk (ERD).

To prevent your network adapter from detecting the link state:

NOTE: NetBEUI and IPX do not recognize Media Sense.

1. Use Registry Editor (Regedt32.exe) to view the following key in the
registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\P arameters

Add the following registry value:

Value Name: DisableDHCPMediaSense
Data Type: REG_DWORD -Boolean
Value Data Range: 0, 1 (False, True) Default: 0 (False)

Description: This parameter controls DHCP Media Sense behavior. If you set
this value data to 1, DHCP, and even non-DHCP, clients ignore Media Sense
events from the interface. By default, Media Sense events trigger the DHCP
client to take an action, such as attempting to obtain a lease (when a
connect event occurs), or invalidating the interface and routes (when a
disconnect event occurs).

2. Restart your computer.

NOTE: There are some side effects of disabling the "Media Sensing" feature. For
example, if you have a machine with two network adapters, and you have the
"Media Sensing" feature enabled, if one network adapter does not work, it is
unbound, and associated routes are removed so that all traffic goes through the
other network adapter (assuming a default gateway is there). Also, if you are a
roaming (portable) user, the "Media Sensing" feature is what provides the
ability to connect to any network and have everything work, without restarting,
release and renewing, and so on. After disabling Media Sense and restarting,
Windows 2000 still shows the "Network Disconnected" icon on the TaskBar and the
'ipconfig' command still shows a "Media State .....: Cable Disconnected" message
when the cable is disconnected. However, the Network Interface is bound to
TCP/IP and you can verify this by looking at the route table --you can use the
"route print" command-- which shows the interface IP address (you are also able
to ping the IP address assigned to the NIC).

Additional query words:

============================================================ ==========
Keywords : kbnetwork kbtool
Technology : kbvcSearch
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbhowto
============================================================ =================
Copyright Microsoft Corporation 2000.


[i]How to Disable Media Sense for TCP/IP in Windows 2000 [Q239924]

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