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

🟢 Flannel Simple Overlay VXLAN tunnel, zero policy K3s

🟠 Calico Policy Powerhouse BGP routing, iptables/eBPF Self-managed

🔵 Cilium eBPF Native Kernel eBPF, replaces kube-proxy GKE (Dataplane V2)

🟡 Weave Net Mesh Overlay Gossip-based mesh routing Self-managed

🟣 Antrea VMware-backed OVS dataplane, Antrea policies Self-managed

🔶 AWS VPC CNI Cloud-native Native VPC IP assignment EKS

🔷 Azure CNI Cloud-native Azure VNET IP assignment AKS

♦️ GKE CNI / Dataplane V2 Cloud-native + eBPF Cilium-based eBPF on GKE…