Virtual Networking Problems With Emulex NICs And Windows Server 2012 R2

Unfortunately, problems have arisen with WS2012 R2 Hyper-V networking where Emulex NICs are used. Hans Vredevoort (Hyper-V MVP) and Marc van Eijk (Azure MVP) have been experiencing this issue and blogged about it on  It appears that lots of you have encountered the same problem with VMs and virtual NICs losing connectivity when a virtual switch is connected to an Emulex NIC – in the guys’ case in HP blades with FlexFabric.

The core issue seems to be related to Emulex 10 GbE NICs – As they guys report in their post Kristian Nese (System Center MVP) also sees the problem on IBM servers with Emulex NICs.

There is no fix. Please watch the thread on to keep up with updates.

5 thoughts on “Virtual Networking Problems With Emulex NICs And Windows Server 2012 R2”

  1. Ouch. I’m in the process of planning several Hyper-V 2012 R2 clusters, with 20+ hosts using IBM x3650 M4 servers with… Emulex 10GbE NICs. System design includes Teaming and full-converged network architecture (several vNICs).
    Time for me to contact the TAM to put pressure on this…

  2. Hi Aidan,
    We are currently tracking this issue with HP and have been given a beta copy of the updated Emulex NIC driver. I will pass on the results of the testing.


  3. Only for the record: HP released new Emulex NIC drivers for Windows Server 2012 R2 on Febuary 18, 2014


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