IN_IFF_TRYTENTATIVE
if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled())
ia->ia4_flags |= IN_IFF_TRYTENTATIVE;
ia->ia4_flags &= ~IN_IFF_TRYTENTATIVE;
(IN_IFF_TRYTENTATIVE | IN_IFF_TENTATIVE | IN_IFF_DUPLICATED)