ot::Ip6::Netif::UpdatePreferredFlagOn() method
Updates the preferred flag on a previously added (internal to OpenThread core) unicast address. If the address is not added to the network interface or the current preferred flag of @p aAddress is the same as the given @p aPreferred, no action is performed.
Arguments
aAddress
The unicast address
aPreferred
The new value for preferred flag.