Changing a MAC address in a Windows virtual machine

Products

• VMware vSphere ESXi

Issue/Introduction

When a physical machine is converted into a virtual machine, the MAC address of the network adapter is changed. This can pose a problem when software is installed where the licensing is tied to the MAC address.

Environment

VMware ESXi 4.0.x Installable
VMware ESXi 4.1.x Installable
VMware ESX 4.1.x
VMware ESXi 4.1.x Embedded
VMware ESX Server 3.5.x
VMware ESXi 3.5.x Embedded
VMware ESX 4.0.x
VMware ESXi 4.0.x Embedded
VMware ESXi 3.5.x Installable

Resolution

An arbitrary MAC address that is not dependent on the VMware MAC Hardware address range can be set from within the network adapter settings in Windows.

Ensure that MAC Address Changes & Forged Transmits are set to Accept. These options are available in the vSwitch and the virtual portgroup security settings before setting the MAC address manually.

To set the address:

1. Open the Device Manager. Click Start > Control Panel > Administrative Tools > Computer Management > Device Manager.
2. Expand Network Adapters.
3. Right-click VMware Accelerated AMD PCNet Adapter or Intel Pro/1000MT and click Properties.
4. Click the Advanced tab.
5. Click NetworkAddress for VMware Accelerated AMD PCNet Adapter or Locally Administered Address for Intel Pro/1000MT.
6. Select Value.
7. Enter the desired MAC address without the colon (:).
8. Restart the virtual machine to ensure that the change takes full effect over the network.
   
   Note: If, after restarting, the Windows guest operating system does not recognize the new MAC, run the getmac command from the Windows command prompt.

Additional Information

Windows 仮想マシンでの MAC アドレスの変更
更改 Windows 虚拟机中的 MAC 地址