| 摘要 |
The present invention relates to a network and, more specifically, to a security system and an operating method thereof. The operating method of the security system according to an embodiment of the present invention comprises the steps of: determining whether each of the packets communicated between a plurality of host computers and the internet is a domain name server (DNS) response packet transmitted from a DNS through the internet; extracting an IP address corresponding to a domain name from the DNS response packet and updating the extracted IP address in an IP address table; and blocking or permitting packets based on the IP address table. [Reference numerals] (111) Security unit; (112) Spinning unit; (120) Internet; (130) DNS server; (141) First server computer; (142) Second server computer; (14n) n^th server computer; (PC1) First host computer; (PC2) Second host computer; (PCk) k^th host computer |
