Kubernetes CNI Complete Guide: Flannel vs Cilium vs Calico + Cloud Provider CNIs

K3s v1.29+ | Flannel v0.24+ | Cilium v1.15+ | Calico v3.27+ | AWS VPC CNI v1.18+ | Azure CNI v1.5+ | GKE Dataplane V2 (Cilium-based) A definitive comparison of every major Kubernetes CNI — open-source plugins (Flannel, Calico, Cilium, Weave, Antrea, Multus) and cloud-managed defaults (AWS VPC CNI on EKS, Azure CNI on AKS, and GKE's Dataplane V2 on GKE) — across architecture, performance, network policy, observability, encryption, and when to choose each. CNI Identity Core Approach Default On 🟢