# Clearing the Machine ID of a Cloned Instance for DHCP Photon OS uses the contents of `/etc/machine-id` to determine the DHCP unique identifier (duid) that is used for DHCP requests. If you use a Photon OS instance as the base system for cloning to create additional Photon OS instances, you should clear the machine-id with this command: echo -n > /etc/machine-id With the value cleared, systemd regenerates the machine-id and, as a result, all DHCP requests will contain a unique duid.