Self-Hosted Kubernetes CNI: Antrea vs Kube-OVN vs Spiderpool (2026)

The Container Network Interface (CNI) is the networking backbone of every Kubernetes cluster. While default plugins like Flannel provide basic pod-to-pod connectivity, production workloads demand advanced features: network policies, load balancing, BGP routing, multi-homing, and hardware acceleration. The choice of CNI directly impacts cluster performance, security posture, and operational complexity.

In this guide, we compare three advanced CNI solutions that go beyond basic connectivity: Antrea, Kube-OVN, and Spiderpool. Each offers a unique approach to Kubernetes networking, from Open vSwitch-based software-defined networking to cloud-native IP address management.

Overview

Antrea

Antrea is a Kubernetes CNI plugin built on Open vSwitch (OVS). Developed by VMware, it provides a software-defined networking (SDN) solution that extends Kubernetes’ native NetworkPolicy API with additional capabilities. Antrea aims to be a complete networking solution for Kubernetes clusters, offering both the data plane (OVS) and the control plane (Antrea Controller).

Key features:

• Open vSwitch-based data plane for flexible packet processing
• Extended NetworkPolicy support (EGRESS, FQDN-based rules, tiered policies)
• Antrea ClusterIdentity for cross-cluster service discovery
• Network flow visualization and troubleshooting tools
• eBPF data plane option (AntreaEP) for higher performance
• Windows node support for hybrid clusters
• Multicast support for stateful applications

Docker/Deployment Configuration

Antrea deploys as Kubernetes DaemonSets and Deployments rather than standalone containers. Here’s the installation manifest approach:

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# Install Antrea CNI (apply to your cluster)
# This is the standard deployment method for CNI plugins
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: antrea-agent
  namespace: kube-system
spec:
  selector:
    matchLabels:
      app: antrea-agent
  template:
    metadata:
      labels:
        app: antrea-agent
    spec:
      hostNetwork: true
      containers:
        - name: antrea-agent
          image: antrea/antrea-agent-ubuntu:latest
          args:
            - --config=/etc/antrea/antrea-agent.conf
            - --logtostderr=false
            - --log-file=/var/log/antrea/antrea-agent.log
          volumeMounts:
            - name: host-var-run-openvswitch
              mountPath: /var/run/openvswitch
            - name: host-var-run-antrea
              mountPath: /var/run/antrea
            - name: antrea-agent-config
              mountPath: /etc/antrea
      volumes:
        - name: host-var-run-openvswitch
          hostPath:
            path: /var/run/openvswitch
            type: DirectoryOrCreate
        - name: host-var-run-antrea
          hostPath:
            path: /var/run/antrea
            type: DirectoryOrCreate
        - name: antrea-agent-config
          configMap:
            name: antrea-config

Antrea Agent Configuration

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# antrea-agent.conf
featureGates:
  AntreaPolicy: true
  Egress: true
  FlowExporter: true
  Multicast: true
trafficEncapMode: encap
serviceCIDR: "10.96.0.0/12"
nodePortAddresses: []
antreaProxy:
  proxyAll: true
  proxyLoadBalancerIPs: true

Kube-OVN

Kube-OVN is a Kubernetes CNI built on OVN (Open Virtual Network), the virtual network abstraction layer used by OpenStack. It brings enterprise-grade networking features to Kubernetes, including VPC isolation, QoS policies, and dynamic subnet management. Kube-OVN bridges the gap between traditional SDN and cloud-native networking.

Key features:

• VPC-level network isolation within a single Kubernetes cluster
• Dynamic subnet creation and management per namespace
• Built-in load balancer with L2/L3/L4/L7 support
• BGP route advertisement for integration with physical networks
• QoS traffic shaping and bandwidth control
• Hardware offload for SmartNICs and DPDK
• VLAN integration for bare-metal deployments

Deployment Manifest

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# Kube-OVN installs as a set of Kubernetes resources
# Key components: kube-ovn-controller, ovn-central, ovs-ovn
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ovn-central
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ovn-central
  template:
    metadata:
      labels:
        app: ovn-central
    spec:
      hostNetwork: true
      containers:
        - name: ovn-central
          image: kubeovn/kube-ovn:latest
          command: ["/kube-ovn/start-ovn-central.sh"]
          env:
            - name: POD_CIDR
              value: "10.16.0.0/16"
            - name: SVC_CIDR
              value: "10.96.0.0/12"
            - name: POD_GATEWAY
              value: "10.16.0.1"
            - name: DATABASE_NORTHS
              value: "4101"
            - name: DATABASE_SOUTHS
              value: "6642"
          volumeMounts:
            - name: host-etc-ovn
              mountPath: /etc/ovn
            - name: host-var-log-ovn
              mountPath: /var/log/ovn
      volumes:
        - name: host-etc-ovn
          hostPath:
            path: /etc/ovn
            type: DirectoryOrCreate
        - name: host-var-log-ovn
          hostPath:
            path: /var/log/ovn
            type: DirectoryOrCreate

Subnet Configuration Example

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# Create a custom subnet for a namespace
apiVersion: kubeovn.io/v1
kind: Subnet
metadata:
  name: production-subnet
spec:
  protocol: IPv4
  cidrBlock: "10.66.0.0/16"
  gateway: "10.66.0.1"
  excludeIps:
    - "10.66.0.1..10.66.0.10"
  gatewayType: distributed
  natOutgoing: true
  private: false

Spiderpool

Spiderpool is a Kubernetes IP address management (IPAM) and network plugin designed for underlay networking. Unlike overlay-based CNIs that encapsulate traffic, Spiderpool assigns real IP addresses from your physical network to pods, enabling direct communication with external services and hardware. It integrates with Multus for multi-homing support and works alongside any CNI.

Key features:

• Underlay networking with real IP addresses (no encapsulation overhead)
• RDMA support for high-performance computing workloads
• Static IP allocation for stateful applications
• IP pool management with automatic reclamation
• Multi-homing via Multus CNI integration
• VLAN and VxLAN support for network segmentation
• Works with any primary CNI (Flannel, Calico, Cilium)

Deployment Configuration

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# Spiderpool coordinator and controller
apiVersion: apps/v1
kind: Deployment
metadata:
  name: spiderpool-controller
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: spiderpool-controller
  template:
    metadata:
      labels:
        app: spiderpool-controller
    spec:
      containers:
        - name: spiderpool-controller
          image: spiderpool/spiderpool:latest
          command: ["spiderpool-controller"]
          args:
            - "--log-level=info"
            - "--coordinator-mutating-webhook-configuration=true"
          env:
            - name: SPIDERPOOL_GIN_ENABLE
              value: "true"
            - name: SPIDERPOOL_GIN_HTTP_PORT
              value: "5721"
          volumeMounts:
            - name: spiderpool-tls
              mountPath: /tmp/spiderpool-tls
      volumes:
        - name: spiderpool-tls
          secret:
            secretName: spiderpool-webhook-cert

---
# IPPool definition
apiVersion: spiderpool.spidernet.io/v2beta1
kind: SpiderIPPool
metadata:
  name: vlan-pool-100
spec:
  subnet: "192.168.100.0/24"
  ips:
    - "192.168.100.50-192.168.100.200"
  gateway: "192.168.100.1"
  vlan: 100

Network Architecture Comparison

The three CNIs represent fundamentally different networking philosophies:

Antrea uses Open vSwitch as its data plane, providing a traditional SDN approach within Kubernetes. OVS is a mature, battle-tested switching technology that supports complex packet processing, flow rules, and tunneling. Antrea extends K8s NetworkPolicy with features like Egress rules and FQDN-based policies that go beyond the native API.

Kube-OVN brings OVN (Open Virtual Network) to Kubernetes. OVN is the networking layer behind OpenStack’s Neutron, providing VPC-level isolation, logical routers, and load balancers. Kube-OVN translates these enterprise networking concepts into Kubernetes primitives — subnets become OVN logical switches, network policies become OVN ACLs.

Spiderpool takes a completely different approach: instead of providing the data plane, it focuses on IP address management for underlay networks. Pods get real IPs from your physical network, eliminating overlay overhead and enabling direct communication with bare-metal services. Spiderpool chains with any primary CNI via Multus.

Why Self-Host Kubernetes Networking?

Choosing and self-hosting your own CNI plugin is critical for production Kubernetes deployments for several reasons:

Performance optimization. Default CNIs like Flannel use VXLAN encapsulation, adding 50+ bytes of overhead per packet. Advanced CNIs like Antrea with eBPF or Spiderpool with underlay networking eliminate this overhead entirely. For high-throughput workloads (databases, media processing, ML training), the difference between 8 Gbps and 25 Gbps network throughput is substantial.

Security and compliance. Network policies are the primary mechanism for implementing zero-trust networking within a Kubernetes cluster. While basic CNIs only support native K8s NetworkPolicy, advanced options like Antrea add FQDN-based rules, Egress policies, and tiered enforcement. For PCI-DSS, HIPAA, or SOC 2 compliance, granular network segmentation is non-negotiable.

Multi-cluster and hybrid cloud connectivity. Enterprises running Kubernetes across data centers or hybrid clouds need CNIs that support BGP route advertisement, VxLAN tunneling, and cross-cluster service discovery. Kube-OVN’s BGP integration and Antrea’s ClusterIdentity features enable these patterns without proprietary add-ons.

Hardware acceleration. Modern data centers deploy SmartNICs, DPDK-enabled NICs, and RDMA fabrics. Kube-OVN’s hardware offload support and Spiderpool’s RDMA integration allow Kubernetes workloads to leverage specialized hardware — critical for NFV, telco, and HPC workloads.

For broader CNI comparisons, see our Flannel vs Calico vs Cilium guide and our Kubernetes network policies deep dive.

FAQ

What is a CNI plugin and why does Kubernetes need one?

The Container Network Interface (CNI) is a specification that defines how network connectivity is provided to containers. Kubernetes relies on CNI plugins to manage pod networking — assigning IP addresses, routing traffic between pods, and enforcing network policies. Without a CNI, pods cannot communicate with each other across nodes.

Should I use an overlay or underlay CNI?

Overlay CNIs (Antrea, Kube-OVN) encapsulate pod traffic in tunnels (VXLAN, Geneve), providing full network abstraction and isolation. Underlay CNIs (Spiderpool) assign real physical network IPs to pods, eliminating encapsulation overhead. Choose overlay for multi-tenant isolation and flexibility; choose underlay for maximum performance and direct access to physical network services.

Can I use multiple CNIs in the same cluster?

Yes, through Multus CNI. Multus acts as a meta-plugin that chains multiple CNI plugins together. You can use one CNI as the primary network (pod-to-pod connectivity) and additional CNIs for secondary interfaces (storage network, monitoring network). Spiderpool is designed to work alongside any primary CNI through Multus.

Which CNI provides the best network policy support?

Antrea provides the most extended NetworkPolicy support, adding Egress rules, FQDN-based policies, tiered policies, and cluster-level network policies on top of the native K8s API. Kube-OVN implements network policies through OVN ACLs which are highly performant but less feature-rich. Spiderpool relies on the primary CNI for network policy enforcement.

Do these CNIs work on bare-metal Kubernetes?

Yes, all three are designed for bare-metal deployments. Antrea supports VLAN trunking and BGP. Kube-OVN has native VLAN integration and BGP route advertisement. Spiderpool excels in bare-metal environments with its underlay networking and RDMA support.

How do these compare to Calico and Cilium?

Calico and Cilium are the most widely adopted CNIs. Calico uses BGP for routing with a focus on performance and policy enforcement. Cilium uses eBPF for programmable networking and security. Antrea competes most directly with Calico (both support network policies), while Kube-OVN offers more enterprise SDN features. Spiderpool is complementary — it can chain with Calico, Cilium, or any other CNI.