In network operation, a variety of network devices must be used together to provide services to users, and an integrated management system is important in a large-scale environment. This paper describes the design and construction of the Tokyo Institute of Technology campus network (Titanet4 : Tokyo Institute of Technology Academic NETwork phase 4), which began phased operation in FY2021. In particular, we describe in detail the configuration management system implemented using open source software (OSS) for continuous operation, and introduce current issues and future prospects.