Overview

OVN-Kubernetes is a free, open-source CNI plugin for Kubernetes, built on OVN and Open vSwitch. It is best suited to teams running complex enterprise or telco clusters that need fine-grained policy, egress control, or more than one network. Its breadth is a real advantage, but secondary-network gaps and version compatibility make cluster design important.

Key features

For core cluster networking, OVN-Kubernetes handles pod IPAM and veth interfaces, GENEVE overlays, Kubernetes Services and EndpointSlices, and IPv4/IPv6 dual stack. NetworkPolicy, AdminNetworkPolicy, and EgressFirewall are enforced through OVN ACLs, bringing policy enforcement into the network layer. AdminNetworkPolicy and BaselineAdminNetworkPolicy are v1alpha1 APIs, though, so teams relying on them must allow for changes before stable v1.

EgressIP, EgressService, and EgressQoS govern how traffic leaves the cluster, while NetworkQoS provides DSCP marking and traffic shaping for pod traffic. These controls matter to operators with differentiated egress or traffic-handling requirements; a cluster needing only basic pod connectivity may not need this level of networking capability.

Multi-homing lets pods attach to multiple networks, with multi-network policies, segmentation, and cross-network connectivity. The current boundary is significant: Secondary User Defined Networks lack north-south traffic and support for core Kubernetes Services. This makes the feature set useful for workloads that need network separation, but a poor fit when those secondary networks must provide ordinary service access or external traffic.

Other specialized capabilities include IGMP snooping and multicast relay, persistent IPs and seamless networking during KubeVirt VM live migration, and Hybrid Overlay VXLAN tunnels for mixed Windows/Linux clusters. OVN-Kubernetes can also offload OVS datapath processing to SmartNICs and DPUs. These features widen its appeal for heterogeneous or performance-conscious infrastructure, but they are relevant only where the corresponding workloads and hardware are part of the design.

BGP Integration supports route advertisements, no-overlay routing, and EVPN, and requires FRR-k8s. The documented CRDs cover EgressIP, EgressService, EgressQoS, EgressFirewall, UserDefinedNetwork, RouteAdvertisements, ClusterNetworkConnect, and VTEP, giving platform teams a substantial API surface to integrate with. Node Identity uses per-node client certificates and a validating admission webhook to constrain ovnkube-node permissions.

Pricing

OVN-Kubernetes is free, with an open-source project rather than paid tiers. That suits teams able to operate the networking stack themselves and removes per-seat or per-token licensing from the decision. The trade-off is operational ownership: the project is self-hosted, and the requirements matrix ties compatibility to OVN, nft, Multus, CNI, and Kubernetes versions.

Supported major releases receive backported fixes and support, with minor patch releases planned every four weeks. The master branch lists Kubernetes 1.33 or newer, so teams should verify the matrix against their intended cluster rather than assume the newest development branch fits an established deployment. Vulnerability reports use GitHub Private Vulnerability Reporting, with an intended response within 48 hours; Dependabot scans the repository for security updates.

Platforms

OVN-Kubernetes supports Kubernetes on Linux and Windows, as well as bare metal, VMware vSphere, IBM Power, IBM Z, and Red Hat OpenStack Platform. Ubuntu- and Fedora-based container images are available in GitHub's Registry. Deployment documentation covers Kind, Helm, DPU acceleration, and kubeadm, alongside source-build instructions. This range gives infrastructure teams several deployment paths, but still assumes a Kubernetes environment and the underlying component versions line up.

Who it's for

This is a strong candidate for platform teams in enterprise and telco environments that need policy controls, dual-stack networking, egress management, multi-networking, or integration with KubeVirt and accelerated networking hardware. Its features can support designs beyond a single flat pod network. Teams with simpler connectivity needs, or those that cannot accommodate secondary-network limitations and version coordination, should consider a narrower option.

Pros and cons

Pros: Broad built-in networking coverage spans IPAM, Services, dual stack, policy enforcement, and egress controls, reducing the need to treat each as a separate capability.
Pros: Multi-homing, multicast, KubeVirt migration support, Windows/Linux overlays, BGP, and SmartNIC/DPU offload address demanding cluster designs.
Pros: Free and open source, with documented deployment routes and a stated major-release fix and support policy.
Cons: Secondary User Defined Networks lack north-south traffic and core Kubernetes Services, limiting designs that depend on those functions.
Cons: AdminNetworkPolicy and BaselineAdminNetworkPolicy remain v1alpha1, so teams building around them face API change risk.
Cons: Version dependencies across OVN, nft, Multus, CNI, and Kubernetes require careful compatibility management; BGP route advertisements also depend on FRR-k8s.

Alternatives

Container Networking Software is a useful comparison set for teams weighing Kubernetes networking approaches. For a security-focused comparison, Microsegmentation Software collects products in that category.

Antrea is another free option for teams seeking a Kubernetes CNI; its plan is 0.00 USD per free and requires a Kubernetes cluster and Open vSwitch kernel module on every node.
HashiCorp Nomad is worth considering for teams evaluating a freemium platform across Linux, macOS, Windows, web, and self-hosted environments.
ColorTokens Xshield is a paid alternative with a free trial for teams comparing security products.
Elisity Microsegmentation is a paid enterprise microsegmentation option.
Trellix Data Loss Prevention suits teams seeking enterprise DLP across endpoints, email, web, networks, and data storage, with on-premises or SaaS management.
Zentera CoIP Access Platform is a paid option for teams comparing access platforms.
Zero Networks Segment is a paid segmentation alternative.
Tetrate Service Bridge is an enterprise-grade service mesh offered hosted or on-premise.

Verdict

Choose OVN-Kubernetes if your Kubernetes platform needs broad network policy and egress controls alongside capabilities such as multi-networking, Windows/Linux operation, KubeVirt migration, or hardware offload. Its open-source, no-cost model and depth make it compelling for teams prepared to manage the version matrix. Look elsewhere if secondary networks must support north-south traffic and core Services, or if a simpler cluster does not justify that operational complexity.

	Cilium	OVN-Kubernetes
Free plan	Yes	No
Free trial	No	No
Paid from	Free	—
Open source	No	No
Platforms	Linux, self-hosted	api, Linux, self-hosted, Windows
Deployment model	hybrid	—
Free plan	—	Yes

Cilium vs OVN-Kubernetes

Cilium

OVN-Kubernetes