Recently, I was building a nested ESXi environment in my lab, based on vSphere 5.5. Regular readers will remember that I generally use VMware Workstation (version 10, in this case) to run my virtual environment.  I usually have my ESXi hosts configured with 8 NICs, which is pretty handy when I have to play with various configurations. The configuration looks something like this:

ESXi VM Configuration

ESXi VM Configuration

After installation, when I got to the stage where I had to add my hosts to a distributed switch, I couldn’t see the uplinks.  I thought I was going mad and went back to check in the Workstation interface, which confirmed that the NICs were indeed still part of the machine.

It was time to double-check what ESXi saw from the command-line and it confirmed this:

One vmnic

That meant only the first vmnic remained and ESXi didn’t know about the rest!

Initially, my suspicion went to the fact that I had a cloned image of ESXi (as per this excellent post by William Lam (@lamw). However, I have since tested this with a fresh installation from scratch and this still happens.

Then, I found this article by VMware.  Now, I hadn’t done anything mentioned in the causes but the symptoms were the same so I thought I should try the workaround mentioned in there.  It worked!

As seen in the screenshot, all vmnics were back:

Eight vmnic

This was strange as I did all the configuration “before” the ESXi install so nothing changed during or after the install.  Also, in the past, I have done numerous installations like this and have never seen this happening.

I haven’t tested this with other versions of VMware Workstation or ESXi so it might be a quirk with this combination but thought I should document this in case it happens to someone else as well.