Over the past couple of months we have seen a number of support requests coming into our HelpDesk around network connection dropouts in Windows Server 2012 Guest systems. Common factor in all these requests where E1000 NICS.


There are known issues with the E1000 NIC and Windows 2012 on ESXi 5.1 and above and the solution to the issue is to use a VMXNET3 NIC over the E1000…and before the VMware bashers start to take aim, lets not forget that the E1000 drivers are written by Intel and are provided as such. The VMXNET3 NICs are VMware written and also provide additional advantages such as better CPU efficiency and the ability to use Jumbo Frames.

Because vCloud Director’s default NIC Type is the E1000, if users are not switched on, then Guest VMs running 2012 will potentially have these issues. To get our support guys proactively advising clients of this issue I put together a quick @CloudPhysics Card using the Card Builder that will report on the Operating System Type, list the Guest NICs and their Type.


Which gives you a report as shown below:


The card should be available in the CloudPhysics Card Store shortly, but it’s easy enough to put together as per the builder blocks and filters above.


In a nutshell for Windows Server 2012…use the VMXNET3! There is really no excuse not to…when provisioning VMs in vCloud Director, be aware that the default NIC is the E1000…Maybe a feature request for the next version vCloud Prod Team? As an additional step, vCloud Users should look to template where possible and include the VMXNET3 NIC as part of the build.

For more info there is good guidance in this KB on selecting NICs based on Virtual Machine Operating System Type…