Hyper-V Virtual Machine Very Slow Network – VMQ – Broadcom

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So couple of days ago I was setting up our new Dell Server running Server 2008 R2 operating system and a Hyper-V role.

After the initial setup was done and Hyper-v role configured it was time to install it’s first VM running Server 2008 R2 as well. Installation went through properly, added all required modules, apps, configs etc.

All good, but when I tried to login to it via one of the workstations I got about 200kbps network speed. At first I thought it could be something wrong with the workstation so I jumped to another client, but the speed was the same. Then thought maybe there is something wrong with the switch that network is using, but on the other hand internet speed was well above 20MBps. Hmmm..

I did another lan speed test but this time between the client and the Hyper-V physical server, the speed was almost a full gigabit! Maybe the ethernet port used by the VM was faulty so i merged both Hyper-V and the VM through the same ethernet port, but still no improvement.

At this point I was really confused (pissed off). I have installed many many VMs using Hyper-V platform, but I never had a similar problem.

To cut the story short, after few hours of troubleshooting I found what was causing the issue. In the Broadcom Network Card configuration “Virtual Machine Queuing” was enabled, which is fine since I have used it before but never had any issues. For some reason I found that the Virtual Machine Queuing” option creates issues with the Broadcom cards using drivers from October. 2012 (mostly used by Dell Servers) After contacting Broadcom they confirmed the same! Well, thanks for wasting my time!

As soon as i disabled the option, VM network speed was great!

Virtual Machine Queue

Hope someone finds this useful!


“Virtual machine queue (VMQ) is a feature available to computers running Windows Server 2008 R2 with the Hyper-V server role installed, that have VMQ-capable network hardware. VMQ uses hardware packet filtering to deliver packet data from an external virtual machine network directly to virtual machines, which reduces the overhead of routing packets and copying them from the management operating system to the virtual machine.


Requirements for VMQ

  • The management operating system must be running Windows Server 2008 R2.
  • The physical network adapter handling the traffic on the management operating system must support VMQ.
  • The virtual machines must be running Windows 7or Windows Server 2008 R2 or running Windows Server 2008 or Windows Vista with the Integration Services Setup Disk installed. Virtual machines running earlier versions of Windows cannot use VMQ. “