• V Uma Rani
• Dr.B.Sateesh Kumar
• Amar Kumar Yadav

Computer network have become increasingly ubiquitous. The world has come to rely on these networks to provide transport for many different mission critical services. However, with the increase in network application, there has also been an increase in difficult for network administrator to control what traffic traverses their network, manage and secure these networks from different attacks. In computer networks, an attack is a security threat that involves an attempt to access, change, damage, reveal information without authorized access or permission. When aim of attack is only to access and get some information from your system but the system resources are not changed or destroy in any way, then it is said to be a passive attack. Active attack occurs where the attacker accesses and either change, disables or destroys your resources or data. There are different types of attacks among which a denial of service attack (Dos) is most common dangerous attacks on network. DoS is one of the active attack on networking structure which force a server to stop from servicing its clients. Network security can be defined as the “The policies and practices adopted to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources”. Failure of network security leads to major threat to various organization such as reputation loss, business loss, service interruption etc. The objective of this paper is to demonstrate the potential damage from DoS attacks and analyze the ramifications of the damage. We will use same penetration testing approach that are used by malicious attacker in order to test network security with one difference, i.e authorization. We will analyze different firewalls and other protective systems and they role in overall security during these attacks. For testing network systems, we will simulate DoS (Denial of Service) attacks on network using GNS3. In our Lab we will be using ipv6 to configure our network.

Computer Network, Network Security, DoS Attack,Virtualization, GNS3, Firewall

"An Empirical Study Of Network Security System Through Dos Attack ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 7, page no.1-8, July-2018, Available :http://www.jetir.org/papers/JETIR1807251.pdf

"An Empirical Study Of Network Security System Through Dos Attack ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 7, page no. pp1-8, July-2018, Available at : http://www.jetir.org/papers/JETIR1807251.pdf