document: Defending against flooding-based distributed denial-of-service attacks : a tutorial Flooding-based distributed denial-of-service -LRB- DDoS -RRB- attack presents a very serious threat to the stability of the Internet . In a typical DDoS attack , a large number of compromised hosts are amassed to send useless packets to jam a victim , or its Internet connection , or both . In the last two years , it was discovered that DDoS attack methods and tools are becoming more sophisticated , effective , and also more difficult to trace to the real attackers . On the defense side , current technologies are still unable to withstand large-scale attacks . The main purpose of this article is therefore twofold . The first one is to describe various DDoS attack methods , and to present a systematic review and evaluation of the existing defense mechanisms . The second is to discuss a longer-term solution , dubbed the Internet-firewall approach , that attempts to intercept attack packets in the Internet core , well before reaching the victim
doc_bio_tags: O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
extractive_keyphrases: tutorial ddos attack methods
abstractive_keyphrases: flooding-based distributed denial-of-service attacks internet stability ddos attack tools large-scale attacks internet firewall attack packets interception reflector attacks distributed attack detection