EricLuehrsen:

odhcpd only gives the ULA to clients in statefu+stateless mode. The original author indicated that this is design intent. But that doesn't work for various devices on an enterprise network. You may want to allow Android devices which only SLAAC+Priv (argh Google!) and any other portable BYOD. However, your enterprise infrastructure is all DHCPv6 addresses only configured from a central location. Every printer has a HOSTID, and when it dies, its replacement gets that HOSTID, such that the HOSTID is building 9, floor 3, row 10, cube AB. Printers are not normally global, but just a small tangible example. In any case, all DHCPv6 addresses should be given or at least an option to do so.

Windows, some smart TV, and some media players often expect to be greedy about grabbing all addresses: DHCPv6, SLAAC, and Priv. They will not accept DHCPv6 with only one-of the prefixes assigned.

Summarizing: openwrt/odhcpd#61