DHCP Uses 100% CPU If First Network Card Is Disabled

• Microsoft Windows NT Server version 4.0

SYMPTOMS

On a multihomed computer, you disable the loading of the network card driver (in Control Panel, double-click Devices) or the driver fails to load because of a problem. Following a restart, you observe excessive CPU usage by the Tcpsvcs.exe process.

CAUSE

When DHCP initializes, it attempts to open a socket on each TCP/IP interface. Because the network card driver was disabled, this results in an error. The DHCP service does not correctly handle this case.

WORKAROUND

To work around this problem, perform the following steps:

1. Go to Control Panel and double-click Network.

2. Click the Bindings tab.

3. Select the network adapter that has the disabled driver.

4. Click Disable, and then click OK.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.