VMWare-ESX-LogoLast week I planned to migrate some virtual machines running on a Windows host with VMWare Server 1.x version to VMWare ESX 3.5i host. One of the vm’s is running as license server and the key is registered by using the MAC of the network interface.

I had the prerequisite of keeping the MAC address of this VM. I first read this post I found with google. http://zealkabi.blogspot.com/2008/09/vmware-esx-server-3x-procedure-to-set.html

I first tried it manually but got the famous error message “The MAC address entered is not in the valid range. Valid values are between xx:xx:xx:xx:xx”

 VMWare ESX Virtual Machine Properties

 Then I removed the vm from ESX inventory; download the vmx file and changed the ethernet0.addressType to static and ethernet0.Address = “01:0C:29:B0:27:E1″ with Notepad++.I deleted original file from the Datastore and upload the vmx file back. I started the vm again and got the message below:

Please specify a static Ethernet address for ethernet0. Failed to configure ethernet0

VMWare ESX Error message static MAC

Without additional setting in the vmx config file you won’t be able to assign a static MAC address in the range your require. To disable mac address checking before boot add the following line in the vmx file.

 ethernetX.checkMACAddress = “false”

Thanks to Jason Nash I fixed this problem.
http://jasonnash.wordpress.com/2008/08/30/disabling-mac-address-checking-in-vmware/

My working config changes:

ethernet0.checkMACAddress = “false”

ethernet0.addressType = “static”

ethernet0.Address = “00:0C:29:B0:27:E1″