Antrea vs Flannel
Antrea
antrea.ioFlannel
github.comSide by side
| Figure | Antrea | Flannel |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | — |
| Windows | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Container Networking Software | 9.0 (#1) | 7.8 (#10) |
| Encryption | Inter-node pod traffic can be encrypted with IPsec or WireGuard tunnels. | The WireGuard backend encapsulates and encrypts packets using the in-kernel WireGuard implementation. |
| Integrations | The documentation lists integrations and guides for Prometheus, Octant, Multus, and Fluentd. | The project lists kube-network-policies, Canal, K3s, and RKE2 as projects that integrate with Flannel. |
| Purpose | Antrea implements the Container Network Interface and Kubernetes NetworkPolicy to provide pod networking and security for Kubernetes workloads. | Flannel provides a layer 3 network fabric for containers designed for Kubernetes. |
| Support | The project directs users to its Kubernetes Slack channel, mailing lists, community meetings, and office hours. | The project points users to the #k3s channel in Rancher Users Slack, the #flannel-users channel in Calico Users Slack, and GitHub issues for bugs. |
Plans
In their own words
Antrea
Antrea provides networking and security for Kubernetes workloads by implementing the Container Network Interface and Kubernetes NetworkPolicy. It uses Open vSwitch as its data plane, including for Kubernetes Service load balancing. Depending on infrastructure and use case, clusters can use VXLAN or Geneve overlays or run without an overlay. Antrea extends Kubernetes policy controls with tiers, rule priorities, cluster-level policies, and Node policies. It can federate clusters with a unified data plane, multi-cluster Services, and security posture. Diagnostics include command-line and UI tools for packet tracing, policy analysis, and flow inspection; metrics can be exported to Prometheus. Pod traffic encryption with IPsec or WireGuard is supported between Linux nodes, but not on Windows nodes. Deployment guides cover Amazon EKS, Azure AKS, and Google GKE, with GKE marked Alpha. The project requires a Kubernetes cluster and the Open vSwitch kernel module on every node, and its overview says it has been tested with Kubernetes 1.23 or later. Antrea is an open-source CNCF sandbox project under Apache License 2.0.
Flannel
Flannel is a free network fabric for containers designed for Kubernetes. A small flanneld agent on each host allocates a subnet lease from a configured address space, then forwards packets between hosts using a selected backend. Documented choices include VXLAN, host-gw, WireGuard and UDP, with VXLAN recommended. WireGuard encapsulates and encrypts packets using the in-kernel WireGuard implementation. Network configuration and subnet allocations can be stored in the Kubernetes API or directly in etcd. The project documents Kubernetes and Docker deployments, with Linux and Windows build instructions. Flannel does not enforce network policies itself, though its Helm chart can deploy a Kubernetes SIGs network policy controller alongside it. It runs as a privileged daemonset with access to the host network, so the security policy advises least privilege and keeping it updated. Security fixes are maintained for the latest release only, and the backend documentation says not to change a selected backend at runtime.