Cilium is open-source software for providing, securing, and observing network connectivity between workloads, powered by eBPF. Its networking use cases include CNI, Layer 4 load balancing, Cluster Mesh, kube-proxy replacement, BGP, service mesh, Gateway API, IPv6, host firewall, and ingress. Identity-aware network policies can enforce rules across L3–L7, including DNS- and HTTP-aware filtering; listed security features also include runtime security and transparent encryption. Encryption options for managed host and endpoint traffic include IPsec, WireGuard, and ztunnel, which is marked beta. Hubble, built on Cilium and eBPF, provides visibility into service communication and behavior. Other observability features include service maps, metrics and tracing export, network flow logs, and protocol visibility. Documentation describes Prometheus and Grafana integrations and Kubernetes support for services including GKE, AKS, EKS, OpenShift, RKE, k3s, and Alibaba ACK. The container image requires AMD64 or AArch64 hosts with 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 points to separate large-environment guidance.
Who it is for
Cilium suits teams managing Linux-based workload networking that need policy enforcement, security, and observability. It is relevant to Kubernetes environments and supports multiple listed distributions and services.
What is good
- Open-source software for workload networking.
- Identity-aware policies cover L3–L7.
- Hubble provides service communication visibility.
- Integrates with Prometheus and Grafana.
What to know first
- Requires AMD64 or AArch64 hosts.
- Requires Linux kernel 5.10 or later, or equivalent.
- Environments above 500 nodes need separate guidance.
- ztunnel encryption support is marked beta.
Verdict
Cilium brings networking, policy, security, and observability features together for Linux workload environments. Check kernel and scale requirements before choosing an installation path.
Cilium plans and pricing
All plansCompared on microsegmentation software
- Deployment model
- hybrid
