Cilium is a networking, security, and observability platform for containerized environments that leverages kernel-level data paths to process traffic. By executing programs directly within the Linux kernel, it provides high-performance packet filtering, routing, and load balancing without the need for traditional user-space proxies or context switching.
The platform distinguishes itself through identity-based security enforcement, which filters traffic based on service labels rather than volatile IP addresses. It integrates containerized workloads with external physical or virtual infrastructure using standard routing protocols and supports multi-cluster connectivity by linking independent environments into a unified network fabric.
Beyond its core networking capabilities, the project provides comprehensive observability into connectivity patterns and security events across distributed systems. It includes features for transparent network encryption, egress traffic control, and automated IP address management to maintain consistent communication and security policies across large-scale deployments.
