# File lib/cidr.rb, line 1907
    def succ()
        bitstep = 2**(@address_len - self.bits)
        next_sub = @network + bitstep

        if (next_sub > @all_f)
            raise BoundaryError, "Returned subnet is out of bounds for IPv#{@version}."
        end

        next_sub = NetAddr.cidr_build(@version,next_sub,self.to_i(:netmask))

        return(next_sub)
    end