A network management apparatus configured to obtain multiple rules that each control communication in accordance with an address range of a packet, divide a full set of the address range of the multiple rules into multiple subsets that are mutually disjoint in accordance with inclusion relations of the address range among the multiple rules, extract, with respect to each rule of the multiple rules, one or more subsets that are included in the address range from the multiple subsets, and determine, with respect to each rule of the multiple rules, an inclusion relation of the one or more subsets between a particular rule and another rule of the multiple rules that is assigned higher priority than that of the particular rule and determine disposition for each of the multiple rules in accordance with a determination result of the inclusion relation of the one or more subsets.