Cilium vs Kube-OVN

Cilium is an open-source, cloud-native system for providing, securing, and observing network connectivity between workloads using eBPF. Its networking capabilities include CNI, Layer 4 load balancing, Cluster Mesh, kube-proxy replacement, BGP, service mesh, Gateway API, IPv6, host firewall, and ingress. Network policies can enforce identity-aware rules from L3 through L7, including DNS- and HTTP-aware filtering. Security features include runtime protection and transparent encryption of managed host and endpoint traffic using IPsec, WireGuard, or ztunnel; ztunnel support is marked beta. For visibility, Cilium lists service maps, metrics and tracing export, network flow logs, and protocol visibility. Hubble, built on Cilium and eBPF, provides visibility into service communication and behavior. Documentation describes Prometheus and Grafana integrations and Kubernetes support for services including GKE, AKS, EKS, OpenShift, RKE, k3s, and Alibaba ACK. Its container image requires AMD64 or AArch64 hosts running Linux kernel 5.10 or later, or an equivalent kernel such as 4.18 on RHEL 8.10. For environments above 500 nodes, the quick installation guide directs readers to large-environment guidance or specific datapath modes.

Kube-OVN combines OVN and Open vSwitch with Kubernetes for cloud-native network orchestration. Its documented features include subnet management, static IP allocation, gateways, hybrid underlay and overlay networks, VPC features, QoS, ACLs, and traffic mirroring. VPC networks provide tenants with separate address spaces and networking resources. The project recommends it for Kubernetes environments needing KubeVirt support or multi-tenant networking; KubeVirt virtual machines can live-migrate without network interruption. Documented integrations include Cilium, MetalLB, OpenStack, Submariner, and OVN interconnect. With Cilium chaining, Kube-OVN network abstractions can be used with Cilium eBPF monitoring and security capabilities. The project runs on x86_64 and arm64, and its documentation provides one-click installation scripts. It is free under Apache-2.0, deployed on-premises, and uses a centralized control plane. The project advises against it for OpenShift, public-cloud managed Kubernetes, and cases requiring an all-in-one CNI, ingress, service mesh, and observability stack.