One final thought on the PMTU work around. Thinking about this more, I don't think the changes to the registry should have any effect. The problem is receiving incoming fragmented packets, not sending fragments, which is what the registy setting change. With that in mind I decided to remove all the suggested registry entries and reboot the VM. After restart I toggled the MTU setting in System Preferences as suggested by Jeff A. It seemed to work just fine for me.