AUTHENTICATION SWITCH OR NETWORK SYSTEM

PROBLEM TO BE SOLVED: To provide a terminal with redirect information to a web server holding authentication information registration screen data by allowing an authentication switch to perform failure monitoring of an external server and using the result.SOLUTION: A life-and-death monitoring control part 305 for performing life-and-death monitoring of an external web server 120 is provided in an authentication switch 100, and life-and-death monitoring of the external web server 120 is performed. An authentication processing part 304 in the authentication switch 100 switches redirect information on the basis of a life-and-death monitoring table 307 of the external web server 120 belonging to the life-and-death monitoring control part 305 in response to an authentication request from a terminal 110, and enables web authentication even during a failure of the external web server 120.