Towards High-Performance Intrusion Detection with Robustness Guarantees on Programmable Switches at ISP Scale

In order to provide security connections to the enterprise campus sites, internet service providers are offering comprehensive intrusion detection services at the network layer. However, existing network intrusion detection systems (NIDS) are either ineffective or inefficient for high-speed network protection, especially for encrypted traffic analysis. In this paper, we design and implement SiteGuard, an inline network intrusion detection system with programmable switches specifically developed to protect enterprise campus sites connecting to ISP. SiteGuard proposes a dual-plane feature extraction model to extract extensive traffic features at near line-speed. SiteGuard also proposes a lightweight one-class classification model that trains the best parameters exclusively on benign traffic to identify malicious traffic. In addition, SiteGuard introduces an online update mechanism that aims to dynamically adjust the detection model in response to environmental changes. SiteGuard has been in production for more than three years. Our production and testbed evaluations demonstrate SiteGuard can detect malicious traffic with approximately 90% accuracy in minutes.