An attack blocking control method uses an access control list (ACL). The method includes investigating the ACL if a packet is input, and checking whether or not the packet is registered in the ACL, comparing a current time count value with a blocking time of the packet if the packet is determined to be registered in the ACL. Further, the method includes increasing the number of blocking times of the packet by 1 if the current time count value is smaller than or equal to the blocking time. Further, the method includes automatically renewing the blocking time, and removing registration information for the packet from the ACL if the current time count value is greater than the blocking time.