I noticed something interesting while extracting the contents of ESXi 5.1 ISO for some kickstart configurations ….

Do you see it? It’s a VMXNET3 driver for the VMkernel! I also confirmed by running the following ESXCLI command querying for the VMkernel module “vmxnet3“:

# esxcli system module get -m vmxnet3
Module: vmxnet3
Module File: /usr/lib/vmware/vmkmod/vmxnet3
License: GPL
Version: Version, Build: 799733, Interface: 9.2 Built on: AugĀ  1 2012
Signed Status:
Signature Issuer:
Signature Digest:
Signature FingerPrint:
Provided Namespaces:
Required Namespaces: [email protected], com.vmware.vmkapi@v2_1_0_0

***Disclaimer***: This is for educational purposes only, this is not officially supported by VMware. Use at your own risk. There is also a mention of this in the vSphere 5.1 release notes that VMs running on nested ESXi hosts using VMXNET3 driver could potentially crash. Again, not supported user at your own risk.

Next I decided to create a Nested ESXi 5.1 VM, but instead of selecting the e1000 driver which was the only network adapter type that would function for running a nested ESXi host, I choose the VMXNET3 adapter and to my surprise ESXi’s networking stack was fully functional.

You can see from the above screenshot, I have a two VMXNET3 network adapters for my nested ESXi 5.1 VM. Here are two additional screenshot of the physical adapters as seen by nested ESXi 5.1 host and you can see that it shows up as VMware Inc. VMXNET3

I have not tried any performance tests, so not sure if there are going to be any significant benefits but pretty cool nonetheless!

7 thoughts on “Nested ESXi 5.1 Supports VMXNET3 Network Adapter Type

  1. Have you experienced the second nic on a nested ESXi5.1 having no networking connectivity? In my lab I was building out nested vSphere, on a vDS I have nic1 on management and nic2 as the vMotion vmk port. For some reason that nic will not have network connectivity. I built an Ubuntu box and put the nics on the same networks and have no issues, it seems only to be ESXi5.1 with the issue.

  2. Hi,
    my experience:
    First I have created Linux Red Hat 6 64bit with 4 vmxnet3 adapters. Then switched to ESX5 OS in Edit Settings. Converted to Template then deployed VM ESXi from it. Deployment Wizard showed me that vmxnet3 network devices are not supported for this configuration of nested ESXi VM. Then I started new nested ESXi VM reset ESXi management network of that nested ESXi to regenerate its vmk0 especially because of MAC address conflict with other nested ESXis. Then enabled vmkernel port of it nested ESXi VM for vMotion and PSOD!!!!
    So looks like you can create and start nested ESXi VM with vmxnet3 network adapter but not working after you modify vmkernel network settings.

  3. I had spend all day testing the vESX with all kinds of different configurations.

    Seems that every time when traffic flows over the VMXNET3 enabled port, ESXi does PSOD.

    Tried to config with management ports on E1000 and only NFS configured with VMXNET3. this seemed to work for a while (couple of minutes) but again PSOD>

    It would be very helpfull to have 10G NFS interfaces in my vESX hosts in my lab. Can’t seem to get it working properly :-(

  4. HI Guys, If any one of you found a fix for the PSOD issue because of vmnet3, please reply.


Thanks for the comment!