Came across an interesting dilemna this morning in our environment. A virtual machine (VM) had no connectivity. After googling various items in regards to loss of connectivity for network in a virtual environment, I finally came across an answer in the VMware community (link). Basically, what we had to do to get it working was disable IPSEC. Because we are on a closed environment, this was possible to do. Once it was disabled, we rebooted the machine and viola, connectivity.