Int. J. Intelligent Engineering Informatics, Vol. 1, Nos. 3/4, 2011 261 Copyright © 2011 Inderscience Enterprises Ltd. Combat model-based DDoS detection and defence using experimental testbed: a quantitative approach G. Preetha*, B.S. Kiruthika Devi and S. Mercy Shalinie Department of Computer Science and Engineering, Thiagarajar College of Engineering, Madurai 625015, India E-mail: preetha@tce.edu E-mail: kiruthi_23@tce.edu E-mail: shalinie@tce.edu *Corresponding author Abstract: Basic model for DDoS detection and prevention needs to be developed primarily to analyse the relationship between attacker and defender. Research in DDoS attacks is mainly focused on qualitative modes than quantitative analysis. The proposed work incorporates Lanchester combat model to quantify the attacker strength thereby giving a clear picture of how a DDoS defence system should be secure and what level of effectiveness is required to mitigate the attack. The work model is divided into online monitoring system (OMS) where network anomalies are monitored using the various performance metrics and offline training system (OTS) differentiates spoofed traffic from normal traffic using hop count filtering (HCF) defence algorithm. The proposed work opens a new platform for researchers to know apriori what defence strategy should be employed for what kind of DDoS attack. The implementation is carried out on a distributed testbed build up on GNU/Linux machines. Keywords: DDoS; analytical model; testbed. Reference to this paper should be made as follows: Preetha, G., Kiruthika Devi, B.S. and Mercy Shalinie, S. (2011) ‘Combat model-based DDoS detection and defence using experimental testbed: a quantitative approach’, Int. J. Intelligent Engineering Informatics, Vol. 1, Nos. 3/4, pp.261–279. Biographical notes: G. Preetha received her BSc in Computer Science in 1997, MSIT in Information Technology in 2000 and MPhil in Computer Science from Madurai Kamaraj University in 2005. She worked as a Lecturer from 2002 to 2008. She is currently working as a Research Associate in Smart and Secure Environment project under IIT, Madras. Her current research interests include network security and wireless adhoc networks. B.S. Kiruthika Devi received her BE in Electronics and Communication Engineering from Coimbatore Institute of Engineering and Information Technology in 2006. She is currently working as a Research Assistant in Smart and Secure Environment project under IIT, Madras. Her current research interests include network security and machine learning.