Returns a NetAddr::IP object corresponding to the first unassigned address
in the block (other than the network, broadcast, or gateway address). If
there are no free addresses, returns nothing. There are never free addresses
when manual_flag is true.
Returns a NetAddr::IP object corresponding to the first unassigned address
in the block (other than the network, broadcast, or gateway address). If
there are no free addresses, returns nothing. There are never free addresses
when manual_flag is true.