--dhcp-duid=<enterprise-id>,<uid>
(IPv6 only) Specify the server persistent UID which the DHCPv6 server
will use. This option is not normally required as dnsmasq creates a
DUID automatically when it is first needed. When given, this option
provides dnsmasq the data required to create a DUID-EN type DUID. Note
that once set, the DUID is stored in the lease database, so to change between DUID-EN and
automatically created DUIDs or vice-versa, the lease database must be
re-initialised. The enterprise-id is assigned by IANA, and the uid is a
string of hex octets unique to a particular device.