If you think about you should uninstall VMtools and reinstall, right? They will be different versions. That’s if you think about it. So what happens if you don’t? I found out.
Keep in mind this only happened to a small number of VMs. The VMware Admin moved a significant portion of the Citrix Xenapp infrastructure to another cluster one night. It was on ESXi 5.1 and now it’s on 5.5.
So what? Nothing at first.
Then we started getting weird network issues. Server A stopped responding to pings for awhile, but now it’s back. Server B lost its static gateway address. Server C has one NIC with an IP of 192.168.1.2 but responds to pings at 192.168.1.15. It also won’t let you change the address of the adapter to 192.168.1.2 because it (correctly) says it is already using that address.
The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter
That last one is what exposed it. Ghosted NICs. So I stumbled on https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1179.
With this, I was able to see and remove the hidden adapter and reboot. But, lo, error persisted. I ended up having to uninstall the active adapter and reboot again. Once it came up, I was able to put in the correct details.
Update: I had a 2008r2 Server that I had to add the System Variable in order to get the deactivated NIC to display.