Cilium vs CNI Plugins

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.

CNI Plugins is a collection of reference and example network plugins for configuring connectivity in Linux and Windows containers. CNI supplies a specification and libraries, plus a command-line tool for executing plugins and a Go library for application integration. Interface options include bridge, ipvlan, loopback, macvlan, point-to-point, VLAN, host-device, and dummy; Windows-specific plugins include win-bridge and win-overlay. IP address management choices cover DHCP, host-local allocation tracking, and static IPv4 or IPv6 allocation. Meta plugins handle interface tuning, port mapping, bandwidth limits, source-based routing, and firewall rules, and a sample plugin illustrates custom plugin development. CNI focuses on connecting containers and removing allocated resources when a container is deleted. The project is distributed under Apache License 2.0 and is a Cloud Native Computing Foundation project. It is free, with a plan listed at free. Linux and Windows are supported; the latest release page lists Linux archives for amd64, arm, and arm64.