There are provided a forward relay unit (31) configured to distribute a request from a radius client (1) which is a facing node of a microservice to the microservice to one of servers (5a and 5b) accommodating the microservice; and
a backward relay unit (34) configured to perform NAPT on a request from the microservice to an address band of the facing node, and return a response from the facing node to the request to the microservice in a reverse order of a path along which the request has passed. Accordingly, in a microservice infrastructure on which an NFV application requiring IP authentication is mounted, it is possible to satisfy a requirement of an application of a request transmitted from a microservice to a facing node.