Apparatus and method for blocking harmful internet site

A method for blocking a harmful internet site by using a system comprising an NAS for administering traffic of internet service subscribers transmitted from a DSLAM;

• a certification server for certifying the subscribers;
• a switching unit for certifying a harmful site blocking service subscriber of the subscribers and for administering traffic of the harmful site blocking service subscriber;
• a blocking server, containing a list on harmful sites, for preventing a subscriber connected to the switching unit from connecting to a harmful site, the method comprising:
• a first process wherein the certification server certifies a subscriber if an internet service subscriber connects to the NAS;
• a second process for transmitting the IP address and subscriber information on the switching unit into the NAS if the subscriber is a harmful site blocking service subscriber as the certification result of the certification server;
• a third process wherein the NAS constitutes a L2TP tunnel toward the switching unit depending on the information and transmits the harmful site blocking service subscriber information using the L2TP tunnel, and the switching unit performs a subscriber certification;
• a fourth process wherein the switching unit assigns the PPP and the IP to the harmful site blocking service subscriber terminal when the subscriber is a legitimate subscriber as the certification result of the switching unit;
• and
• a fifth process wherein the blocking server supervises an internet traffic of the harmful site blocking service subscriber through the switching unit, and blocks traffic transmission of a subscriber who connects to a harmful site.