A relay device that monitors and controls common public radio interface (CPRI) links that are links using CPRIs functioning as interfaces for connecting multiple relay devices included in a radio base station detects a disconnected CPRI link by monitoring, via the CPRI links, relay information containing communication data and control data. The relay device distributes a control content, such as a forced link disconnection that forcibly disconnect a CPRI link or no-transmission that stops the transmission of the communication data, with respect to each CPRI link in accordance with a connecting location of the CPRI link in which a link disconnection is detected. The relay device monitors and controls each CPRI link.