Environment:
Windows Server 2008 R2 Core, Hyper-V Server 2008 R2.
Cause:
This occurs on Windows Server 2008 R2 Core and Hyper-V Server 2008 R2 due to a Microsoft issue where a large number of hidden, unused network tunnel adapters are generated.
PowerChute Network Shutdown (PowerChute) uses the Java API called "NetworkInterface.GetNetworkInterfaces" to retrieve a list of network adapters on the machine for certain functions: e.g., opening ports for the Web UI or loading some pages in the UI.
The Java API calls a native Microsoft API function "GetIfTable". This function retrieves all of the network adapters including the hidden ones. The number of adapters can grow to approximately a thousand over the course of a few days. This causes a delay in performing network-related functions in PowerChute.
Resolution:
1. Install Service Pack 1 (SP1) for Windows 2008 R2/ Hyper-V Server R2. This prevents additional tunnel adapters from being created.
2. Contact Microsoft Technical Support and request a copy of the "NDISCLEANUP Tool". This tool can be run after installing SP1 to remove the unwanted tunnel adapters from the system and prevents Java from processing them.