Calico Open Source vs OVN-Kubernetes

Calico Open Source provides networking, network security, and observability for Kubernetes across multi-cloud, hybrid-cloud, and on-premises environments. It supports container, virtual machine, and bare-metal workloads with a shared security policy framework. The policy engine implements Kubernetes network policy features including AdminNetworkPolicy and BaselineAdminNetworkPolicy. Policies can use tiers, deny and log actions, NetworkSets, and cluster-wide global rules; Staged Policies allow teams to assess behavior before applying enforcement. Listed data planes include eBPF, iptables, nftables, Windows, and VPP. Whisker provides a visual way to view flow logs and analyze network communication. Calico can also manage WireGuard tunnels to encrypt pod traffic between Kubernetes nodes. Calico Ingress Gateway provides traffic control, load balancing, and ingress policy enforcement. The free plan includes unlimited clusters, with in-memory data retention and community-driven support and maintenance. Tigera describes deployments ranging from 10 to 10,000 or more nodes.

OVN-Kubernetes is a free, open-source networking solution and CNI-conformant plugin for Kubernetes, built on OVN and Open vSwitch. It handles pod IP allocation and interfaces, GENEVE overlays, Kubernetes Services, EndpointSlices, network policies, and IPv4/IPv6 dual-stack clusters. OVN ACLs enforce NetworkPolicy, AdminNetworkPolicy, and EgressFirewall rules; EgressIP, EgressService, and EgressQoS govern outbound traffic. Pods can join multiple networks, and the project also supports multicast, traffic shaping, BGP route advertisements, and SmartNIC or DPU offload. For KubeVirt, it provides persistent IPs during live migration; Hybrid Overlay enables mixed Windows and Linux networking. Deployment documentation covers Kind, Helm, DPU acceleration, kubeadm, and source builds. Requirements depend on 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. AdminNetworkPolicy APIs remain alpha and may change before stable v1.