I deployed a Debian VM from the public catalogue. I then requested vCloud Director to give it an IP address from the Static IP Pool. This showed as being successful in the VCD portal but I could not ping the VM when it was powered on. I logged in via the console and the VM had not recieved the IP address. Within the properites of the VM I noticed Enable guest customization was not ticked.  When I tried to tick this and press OK I received the following message:

Guest customization is not supported by the selected OS. Please disable guest customization to proceed.

Upon inspecting the supported operating systems for VCD 5.5 it appeared Debian was not on the list.

However, there is a work around.  To enable this feature all we have to do is change the OS from Debian to Other Linux in the properties of the VM.

I then powered up the VM and the guest customization completed successfully