When you connect to a VMWare server behind a NAT device via the vSphere client, you are unable to get console access for virtual machines. The vSphere client returns an error like "Unable to connect to the MKS: Failed to connect to server x.x.x.x:903."
Solution:
Add the following line to /etc/vmware/config:
vmauthd.server.alwaysProxy="TRUE"
If the NAT device is also doing firewalling, make sure that port 903/tcp is open for traffic from your local IP to the VMWare server and vice versa.
More Information:
I originally found the solution on VMWare's forums here. This thread provides more information about the issue. Apparently this is expected to be fixed a future update.
