Optical network management device, optical network system, optical network management method, and optical network management program

An optical network management device (100) which assigns a path from a transmitting node to a receiving node in an optical network system including a multi-core optical fiber, includes at least one processor, the processor being configured to carry out: a core extraction process of extracting a core constituting the path; and a path assignment process of selecting, in accordance with an attribute of the path, a wavelength to which the path is to be assigned, the multi-core optical fiber having an optical amplifier attached thereto, the optical amplifier having an amplification gain that is larger in a first wavelength region than in a second wavelength region, the path assignment process including preferentially assigning, to the first wavelength region, the path having a specific attribute.