What is IPS?

IPS is the active counterpart to IDS. By sitting inline in the network path, an IPS drops malicious traffic before it reaches its target. This requires low-latency inspection engines that process traffic at line rate without introducing unacceptable delays.

Modern IPS systems combine signature databases (updated continuously by threat intel feeds), protocol anomaly detection, and statistical analysis. They also apply rate limiting to mitigate DoS attacks and enforce protocol compliance (dropping malformed HTTP requests, for example).

Next-generation firewalls incorporate IPS as a feature, making standalone IPS appliances less common. However, IPS logic remains critical in NGFW rulesets and cloud-native security groups. The risk of false positives causing legitimate traffic drops means IPS tuning requires careful validation before moving signatures from detection-only to blocking mode.