# Cilium

> eBPF networking, security, and observability for Kubernetes

**Category:** DevOps  
**Pricing:** open-source  
**URL:** https://cilium.io  
**GitHub:** https://github.com/cilium/cilium  
**Added:** 2026-09-21

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## The Hook

Cilium replaces kube-proxy-era networking with eBPF datapaths for identity-aware network policy, load balancing, and Hubble observability.

## What's Good

Apache-2.0 (cilium/cilium). CNCF-graduated Kubernetes networking/security/observability stack built on eBPF: L3–L7 policy, service mesh options, encryption, and Hubble flow visibility. The free path is the OSS project you run; docs at docs.cilium.io and product site at cilium.io.

## The Catch

Vs flannel/Calico defaults: Cilium is the deeper eBPF control plane — more power, more kernel/datapath expertise. Isovalent/Cisco commercial layers exist around the same codebase; self-host OSS carefully for upgrades and Hubble ops.

## Verdict

Apache-2.0 eBPF Kubernetes networking. Default when identity-aware policy and Hubble flows beat plain CNI.