Unlike DHCPv4, which is invoked by manual configuration, DHCPv6 is invoked by Router Advertisements (RAs). Depending on how the router is configured, the system automatically invokes DHCPv6 on the interface on which the Router Advertisement message was received and uses DHCP to get an address and other parameters, or the system requests only data other than an address (for example, DNS servers) with DHCPv6. On DHCPv6 networks, the in.ndpd daemon provides host autoconfiguration.
The in.ndpd daemon receives the Router Advertisement message automatically on all interfaces plumbed for IPv6 on the system. When in.ndpd detects an RA that specifies that DHCPv6 should run, it invokes DHCPv6.
To prevent in.ndpd from starting DHCPv6, you can change the /etc/inet/ndpd.conf file.