Friday, 8 January 2010

Hyper-V Server 2008 R2 – Error Applying New Virtual Network Changes – Binding failed . . . because it is already bound to another virtual network

UPDATE 2011-07-09: The Hyper-V Server 2008 R2 SP1 (Windows Server 2008 R2 SP1) fix is here:

This one was a bit weird. We went to bind a virtual switch to one of the Node’s NICs with the binding process getting hung up.

Eventually, we had an empty Virtual Network Manager as that was the first External virtual network we were creating.

So, we went to try again, but ended up with this:


Virtual Network Manager

Binding to the external ethernet (sic) ‘Intel® 82575EB Gigabit Network Connection #2’ failed.

Cannot bind to ‘Intel® 82575EB Gigabit Network Connection #2’ because it is already bound to another virtual network.

Ouch. In our initial searches for the solution, we came up with reinstall the OS.

But, we turned up this gem:

The commands to run at the command prompt to fix the problem are as follows:

  1. netcfg -u vms_pp [Enter]
  2. netcfg -l c:\windows\winsxs\amd64_wvms_pp.inf_31bf3856ad364e35_6.1.7600.16385_none_beda85050b13680c\wvms_pp.inf -c p -i vms_pp
    • After this command, flip over to the console and check the network settings. They should look like:
    • image
  3. In Hyper-V Manager, remove any External Virtual Networks in Hyper-V Management for the affected Node or Hyper-V Server 2008 R2 server.
  4. From the Hyper-V Management system, run a ping from the command line to verify what IP address is being used to connect to the Hyper-V Server 2008 R2 Node or box.
  5. If the IP being used is incorrect:
    1. Change the DNS setting on the DC to the correct one. In this case it is
    2. IPConfig /FlushDNS [Enter]
    3. ping hyper-v [Enter}
      • This result should be the correct IP.
  6. If correct, create the External Virtual Networks needed in Hyper-V Manager.

Please make sure to copy and paste step 2 into notepad just in case the blogging service inserted any errant hidden characters.

Once we had a successful External Virtual Network configuration, our console looked like:


We then had the extra two NICs on all three nodes bound to an External Virtual Network with the Allow management operating system to share this network adapter not checked. With that, we had the configuration we needed to move forward.


We are now ready to run our what is hopefully our last Validate a Configuration test in the Failover Clustering Manager!

Thank you to fellow MVP  Mikael Nystrom (his blog) for his input on the NIC setup!

Philip Elder
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book

*Our original iMac was stolen (previous blog post). We now have a new MacBook Pro courtesy of Vlad Mazek, owner of OWN.

Windows Live Writer


Jeremy - 1-Place said...

Before you dive into all that, you might just want to check that someone hasn't checkmarked the binding: 'Microsoft Virtual Network Switch Protocol' to the physical NIC properties. This is checked by the Virtual Network Manager itself AFTER you setup the virtual switch and it will exhibit the error above if someone turned it on themselves.


Anonymous said...

Thanks Jeremy, that saved me a lot of time.