Issue:
When you power on a Virtual Machine (VM) you receive the following error message.
00:01:02:03:04:05 is not an allowed VPX assigned Ethernet address.
Invalid MAC address specified.
Failed to configure ethernet0.
Cause:
There are two possible causes.
1) The Guest Operating System for the VM was accidently changed to an OS type that does not support the Enhanced VMXNET Network Adapter. For example Windows 2003 Standard is such as OS.
2) You have manually configured the following settings in the VMX file of a Virtual Machine that does not support the Enhanced VMXNET Network Adapater.
a. ethernet0.virtualDev = “vmxnet”
b. ethernet0.features = “15”
c. ethernet0.addressType = “vpx”
In both cases this issue is not caused by the actual OS that the VM is running. The issue stems from the “Guest Operating System” setting that is configured in the VM Properties as shown in the following screen shot.
The error is caused because the “vpx” address type is not supported on when the Guest OS type is specified as a Windows 2003 Standard Editions (and possibly other OS types as well). The “vpx” setting is supported on Windows 2003 Enterprise Editions (and possibly other OS types as well).
Solution:
Method 1
If you have accidently changed the “Guest Operating System” setting, then you should revert the setting back to an OS setting that supports the Enhanced VMXNET Network Adapter. For Example, any Windows 2003 Enterprise Edition setting supports the Enhanced VMXNET Network Adapter.
Method 2
If you have manually changed settings in the VMX file in an attempt to make an unsupported OS type use the Enhanced VMXNET Network Adapter you have configured a setting incorrectly.
The proper setting for ethernet0.addressType when used on an unsupported OS type is “generated”. Configure the following setting in the VMX file.
ethernet0.addressType = “generated”
If this does not resolve the issue, remove the following settings to revert back to the Flexible (or E1000) Network Adapter.
ethernet0.virtualDev = “vmxnet”
ethernet0.features = “15”
As always only modify the VMX file when the VM is powered off.