Event ID 12671 — NIC Configuration

Updated: April 7, 2009

Applies To: Windows Server 2008

This is preliminary documentation and subject to change.

This Aspect refers to network switchport, static and dynamic MAC address issues.

Event Details

Product: Windows Operating System
ID: 12671
Source: Microsoft-Windows-Hyper-V-Worker
Version: 6.0
Message: The switch port connection for "%4" is already in use.


Change the switch port of the NIC

Turn Off the virtual machine.

Note: Turning off a virtual machine is equivalent to powering off a computer, so data loss is possible.

Change the virtual machine NIC settings to point to a different/valid switch port, and then restart the virtual machine.


The virtual machine starts and runs network operations without any problems.

NIC Configuration