OVN-Kubernetes

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What OVN-Kubernetes is

OVN-Kubernetes is an open-source networking solution and CNI plugin for Kubernetes, built on OVN and Open vSwitch. It provides pod networking, IP address management, GENEVE overlays, Kubernetes Services and EndpointSlices, network policies, and IPv4/IPv6 dual-stack support. OVN ACLs enforce network policies and egress firewalls, while EgressIP, EgressService, and EgressQoS help manage outbound traffic. Pods can connect to multiple networks, and the project also supports multicast, traffic shaping, BGP route advertisements, and SmartNIC or DPU offload. For KubeVirt, it supports persistent IPs during live virtual-machine migration; Hybrid Overlay enables mixed Windows and Linux clusters. Deployment documentation covers Kind, Helm, kubeadm, DPU acceleration, and source builds. Requirements vary by OVN, nft, Multus, CNI, and Kubernetes versions; the master branch lists Kubernetes 1.33 or newer. Secondary User Defined Networks currently lack north-south traffic and core Kubernetes Services support. The software is free and focuses on networking needs relevant to enterprise and telco users.

Who it suits

It suits teams building Kubernetes networks, particularly enterprise and telco users needing policy controls, egress management, or multi-network capabilities. Users should account for the stated limits on Secondary User Defined Networks and the version requirements.

What it does well

Free and open source.
Supports IPv4/IPv6 dual-stack networking.
Provides network policies and egress controls.
Supports mixed Windows and Linux clusters.
Offers BGP integration and hardware offload.

What to know first

Secondary User Defined Networks lack north-south traffic.
Secondary User Defined Networks lack core Kubernetes Services support.
AdminNetworkPolicy APIs are v1alpha1 and subject to change.
Route Advertisements requires FRR-k8s.

Limits

Secondary User Defined Networks currently lack north-south traffic and core Kubernetes Services support. AdminNetworkPolicy and BaselineAdminNetworkPolicy are v1alpha1 APIs that may change before reaching stable v1.

Getting started

Visit the OVN-Kubernetes website.
Review the documented OVN, nft, Multus, CNI, and Kubernetes requirements.
Choose a documented deployment route: Kind, Helm, DPU acceleration, or kubeadm.
Follow the project's deployment instructions, or use its source-build instructions.

Verdict

OVN-Kubernetes covers core Kubernetes networking alongside policy enforcement, egress controls, multi-networking, and specialized capabilities such as BGP and hardware offload. Check its version requirements and secondary-network limitations against your cluster needs.

Questions

How much does OVN-Kubernetes cost?

It is free, with a free plan.

What platforms does it support?

The listed platforms include Kubernetes, Linux, Windows, bare metal, VMware vSphere, IBM Power, IBM Z, and Red Hat OpenStack Platform.

Does it support network policies and egress controls?

Yes. It supports NetworkPolicy and AdminNetworkPolicy, as well as EgressIP, EgressService, EgressQoS, and EgressFirewall.

Does it support mixed Windows and Linux clusters?

Yes. Hybrid Overlay uses VXLAN tunnels for mixed Windows and Linux cluster networking.

What does it require?

Its requirements matrix covers OVN, nft, Multus, CNI, and Kubernetes versions. The master branch lists Kubernetes 1.33 or newer.

What are the limits of secondary networks?

Secondary User Defined Networks currently lack north-south traffic and core Kubernetes Services support.

Facts from OVN-Kubernetes's own pages

Advanced networking: It supports hybrid Windows/Linux networking, IP multicast, OVS hardware offload, and secondary or local networks. · ovn-kubernetes.io, 1 Oct 2026
API surface: OVN-Kubernetes documents Custom Resource Definitions for EgressIP, EgressService, EgressQoS, EgressFirewall, UserDefinedNetwork, RouteAdvertisements, ClusterNetworkConnect, and VTEP. · ovn-kubernetes.io, 1 Oct 2026
Audience: The project says its features are critical to enterprise and telco users and aims to provide a scalable, performant Kubernetes networking platform. · ovn-kubernetes.io, 1 Oct 2026
BGP dependency: The Route Advertisements feature requires FRR-k8s. · ovn-kubernetes.io, 1 Oct 2026
BGP integration: Route Advertisements integrates BGP to import provider-network routes into OVN pod networks and export pod and egress-IP routes to BGP peers. · ovn-kubernetes.io, 1 Oct 2026
Container platforms: Ubuntu- and Fedora-based container images are available in GitHub's Registry. · ovn-kubernetes.io, 1 Oct 2026
Core networking: It provides pod IPAM and veth interfaces, GENEVE overlay networking, Kubernetes Services and EndpointSlices, NetworkPolicies, AdminNetworkPolicies, and IPv4/IPv6 dual-stack support. · ovn-kubernetes.io, 30 Sept 2026
Dependencies: The requirements matrix lists OVN, nft, Multus, CNI, and Kubernetes versions; the master branch lists Kubernetes 1.33 or newer. · ovn-kubernetes.io, 30 Sept 2026
Deployment: It can be deployed on Kubernetes with Helm or kubeadm, run in Kind for development and testing, and installed with DPU acceleration. · ovn-kubernetes.io, 1 Oct 2026
Egress controls: It supports Multiple External Gateways, DSCP QoS, EgressIP, EgressService, and Egress Firewall controls. · ovn-kubernetes.io, 1 Oct 2026
Founded: 2014 · ovn-kubernetes.io, 28 Sept 2026
Hardware acceleration: OVN-Kubernetes can offload OVS datapath processing to SmartNICs and DPUs. · ovn-kubernetes.io, 30 Sept 2026
Kubernetes networking: It provides pod networking, IPAM, veth interfaces, GENEVE overlays, Kubernetes Services, EndpointSlices, NetworkPolicies, AdminNetworkPolicies, and IPv4/IPv6 dual-stack support. · ovn-kubernetes.io, 1 Oct 2026
KubeVirt integration: It provides persistent IPs and seamless networking for KubeVirt virtual-machine live migrations. · ovn-kubernetes.io, 1 Oct 2026
Multicast: OVN-Kubernetes supports IGMP snooping and multicast relay through OVN. · ovn-kubernetes.io, 30 Sept 2026
Multi-networking: Pods can attach to multiple networks using multi-homing and multi-network policies. · ovn-kubernetes.io, 30 Sept 2026
Multinetworking: Pods can attach to multiple networks using multi-homing and multi-network policies. · ovn-kubernetes.io, 1 Oct 2026
Network security: NetworkPolicy, AdminNetworkPolicy, and EgressFirewall are enforced through OVN ACLs. · ovn-kubernetes.io, 30 Sept 2026
Network segmentation: Its feature set includes user-defined networks, network segmentation, and cross-network connectivity. · ovn-kubernetes.io, 1 Oct 2026
Node security: Node Identity uses per-node client certificates and a validating admission webhook to enforce granular ovnkube-node permissions. · ovn-kubernetes.io, 1 Oct 2026
Policy maturity: AdminNetworkPolicy and BaselineAdminNetworkPolicy are v1alpha1 APIs subject to change before stable v1. · ovn-kubernetes.io, 1 Oct 2026
Purpose: OVN-Kubernetes is an open-source Kubernetes networking solution and CNI-conformant plugin built on OVN and Open vSwitch. · ovn-kubernetes.io, 30 Sept 2026
Quality of service: NetworkQoS provides DSCP marking and traffic shaping for pod network traffic. · ovn-kubernetes.io, 30 Sept 2026
Secondary-network limit: Secondary User Defined Networks currently lack north-south traffic and core Kubernetes Services support. · ovn-kubernetes.io, 30 Sept 2026

Where OVN-Kubernetes stands on Freedom251

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