Network management apparatus and switching apparatus

A network management apparatus is for managing a plurality of switching devices that relay data through a data communication network. The network management apparatus includes a configuration information storage, a connectivity relationship detector and a configuration information modifier. The configuration information storage stores first configuration information. The first configuration information is configured in the switching devices and includes information to be determined in accordance with connectivity relationships among the switching devices. The connectivity relationship detector detects changes of connectivity relationships among the switching devices. The configuration information modifier dynamically modifies the first configuration information in accordance with detected changes of connectivity relationships.