Windows Server 2008 R2 - Hyper V has 3 VMs and randomly (sometimes days apart or weeks) a VM will lose the network connection. By lose I mean that a limited connectivity message appears over the VM's NIC. The problem goes away if the VM is rebooted (i haven't tried to disable and re enable the NIC, I'll try this the next time it happens).

I can't find any error logs on the hyper v server or VM that points to anything when this issue happens.

The hyper-v has 2 NICs one is used as a bridge for the virtual switch for the VMs.

Any ideas on tracing this down more?

  • What kind of NICs are you using? No not use anything but Intel, Broadcom, Emulex, QLogic, Mellanox, and similar Server-grade NICs. This is a very common problem with Realtek, Marvel, NVidia and similar cheap NICs.
    – Chris S
    May 19, 2012 at 2:10

1 Answer 1


Are you using Broadcom NICs

We had the same problem for over 6 months. Tried to rebuild our server core, applied all patches, disabled the ipv4 offsend, updated the NIC drivers , recreated the teams on the NICs and disabled the teams. Nothing worked. In the end, I purchased two intel NICs , disabled the inboard broadcom NICs , created the team and bang!!! Server has been running like a dream. No connection losses, stable and running smooth

Dont bother messing about trying to find a solution, replace the NICs with intel. Will save you loads of time and in our case money

Oh and by the way, ms and dell both said it had nothing to do with the Broadcom NICs. We have prOved then wrong

  • Your Broadcom NICs were probably using outdated firmware or drivers. We only use Broadcom NICs and have not had any problems if they're kept reasonably up to date.
    – Chris S
    May 19, 2012 at 2:08

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