The provisioning file location is discovered using DHCP offer Options 66, 67, or 43, and is downloaded using HTTP or FTP.
The provisioning file URL can be resolved using DNS, in which case up to three DNS server IP addresses should be present in the DHCP offer using Option 6 (IPv4). The DHCP DNS is only used for resolving the provisioning file URL, and not for resolving the URLs of the files named within the provisioning file.
ZTP does not support Option 15 domain names; the URL of the provisioning file should be in ‟host/domain” format, or a simple IP address should be used.