URL FILTERING DEVICE

PROBLEM TO BE SOLVED: To obtain high-speed transfer processing in a gateway when used as a URL filtering system, by generally using a fast path without distinction of an uplink and a downlink.SOLUTION: At the step of receiving a DNS request transmitted before HTTP communication, FQDN included therein is inquired of an AC server in which safety is recorded for each FQDN and IP address. If the safety of the whole contents in the IP address is guaranteed, the whole TCP sessions to the IP address are regarded to be safe, so that the fast path processing is performed. Since the inquiry is made before the establishment of an HTTP session, prompt registration of the fast path can be obtained.