In this paper, we describe and analyze a network based DoS attack for IP based networks. It is known as SYN flooding. It works by an attacker sending many TCP connection requests with spoofed source addresses to a victim's machine. Each request causes the targeted host to instantiate data structures out of a limited pool of resources to deny further legitimate access.

The paper contributes a detailed analysis of the SYN flooding attack and existing and proposed countermeasures. SYN flooding attacks in application Performance Validation with VoIP gives improper results. To overwhelm it, IPv6 approaches have been proposed here with successful implementation it with Network Tester using Moonerv6 Phases algorithms. Agilent Network Tester practices on the same principles to make availability of IPv6 service in Networks or sensor networks.

1. Introduction

The attack exploits weaknesses in the TCP/IP (Transmission Control Protocol/Internet Protocol) protocol suite. This cannot be corrected without significant modifications to its protocols. This denial of service attacks can be launched with little effort. Presently, it is difficult to trace an attack back to its originator.

Several possible solutions to this attack have been proposed by others, and some implemented. We have proposed and developed a monitoring tool in IPv6 that classifies IP source addresses with high probability as being falsified or genuine. Our approach finds connection establishment protocol messages that are coming from forged IP addresses, and takes actions to ensure that the resulting illegitimate half-open connections are reset immediately to work over VoIP applications.

2. Background

We will provide a brief description of the features of the TCP/IP protocol suite that facilitate this attack.

2.1. Internet Protocol

The Internet Protocol (IP) is the standard network layer protocol of the Internet that provides an unreliable, connection-less, best-effort packet delivery service. IP defines the basic unit of data transfer used throughout an IP network, called a datagram. The service is unreliable, because the delivery of datagrams is not guaranteed. Datagrams may be lost, duplicated, delayed, or delivered out of order. IP is connection-less, because each packet is treated independently of others — each may travel over different paths and some may be lost while others are delivered. IP provides best-effort delivery, because packets are not discarded unless resources are exhausted or underlying networks fail. Datagrams are routed towards their destination. A set of rules characterize how hosts and gateways should process packets, how and when error messages should be generated, and when packets should be discarded.

About the Author: Suhas A Desai

  • Undergraduate Computer Engineering Student,Walchand CE,Sangli,INDIA.

  • Previous Publications in area "Linux Based Biometrics Security with Smart Card" are include:ISA EXPO 2004,InTech Journal,TX,USA,IEEE Real Time and Embedded System symposium 2005,CA,USA.,e-Smart 2005,France.

  • Writes security newsletters and features for many security sites.