Instead of entering computer names and IP addresses for virtual NICs when you customize guest operating systems, you can create a custom application and configure it in such a way that vCenter Server generates the names and addresses.

The application can be an arbitrary executable binary or script file appropriate for the corresponding operating system in which vCenter Server is running. After you configure an application and make it available to vCenter Server, every time you initiate a guest operating system customization for a virtual machine, vCenter Server runs the application.

The application must comply with the reference XML file in the VMware knowledge base article at


Verify that Perl is installed on vCenter Server.


  1. Create the application and save it on the vCenter Server system's local disk.
  2. Select a vCenter Server instance in the inventory.
  3. Click the Configure tab, click Settings, and click Advanced Settings.
  4. Click Edit and enter the configuration parameters for the script.
    1. In the Name text box, enter
    2. In the Value text box, enter c:\ and click Add.
    3. In the Name text box, enter
    4. In the Value text box, enter the path to the script file on the vCenter Server system and click Add. For example, enter c:\
    5. In the Name text box, enter
    6. In the Value text box, enter c:\perl\bin\perl.exe and click Add.
  5. Click OK.


You can select the option to use an application to generate computer names or IP addresses during guest operating system customization.