This paper defines a methodology for the evaluation of a Rate-based Intrusion Prevention System (IPS) for a Distributed Denial of Service (DDoS) threat. This evaluation system uses realistic background traffic along with attacking traffic, with four different DDoS attacks. The evaluation metrics are defined using Snort for: rate of packet loss; time to respond; available bandwidth; latency; reliability; CPU loading; and memory usage. The results show that system is effective in handling a low-throughput DDoS attack, but when a rate of 6 000 pps of malicious traffic is reached, Snort starts to drop malicious and legitimate packets, in at the same rate of loss. It also shows that the IPS operates well up to traffic throughputs up to 1Mbps.
Buchanan, W. J., Flandrin, F., Macfarlane, R., & Graves, J. (2011). A methodology to evaluate rate-based intrusion prevention system against distributed denial-of-service (DDoS). In Cyberforensics 2011