PXE-boot, filter on MAC address?

Hi all,

Is it possible to filter out machines from the PXE boot based on MAC address?

We have devices (ip telephones) that we don't want to get a reply from the ZCM servers, and I was hoping there would be a way to filter on their MAC address. Otherwise, we'd have to either put them on a separate VLAN or disable PXE booting on those devices, but that would be a tedious task...

Regards,
Pär