It does work but you need to shutdown the VM first.
Do a vm.off "VMNAME"
Then do the following, Example:
vm.nic_update Test 50:6b:8d:f6:d0:9c network=VLAN 51
Already have an account? Login
Enter your username or e-mail address. We'll send you an e-mail with instructions to reset your password.
Sorry, we're still checking this file's contents to make sure it's safe to download. Please try again in a few minutes.
Sorry, our virus scanner detected that this file isn't safe to download.