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SPECIFICTION
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Cilium

cilium.io

Free plan LinuxSelf-hosted
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Spec score 8.0 #3 of 26 in Software-Defined Networking Software

What it is

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.

Spec sheet

Purpose
Cilium is an open source, cloud native solution for providing, securing, and observing network connectivity between workloads, powered by eBPF.Read 3 Oct 2026 · cilium.io
Integrations
Cilium documentation describes integrations with Prometheus and Grafana for metrics and dashboards.Read 3 Oct 2026 · docs.cilium.io
Community support
Cilium documentation directs users to its FAQ, Slack channels, and GitHub issue tracker for help and bug reports.Read 3 Oct 2026 · docs.cilium.io
Encryption
Cilium supports transparent encryption of managed host and endpoint traffic using IPsec, WireGuard, or ztunnel; ztunnel support is marked beta.Read 3 Oct 2026 · docs.cilium.io
Hubble
Hubble is a distributed networking and security observability platform built on Cilium and eBPF that provides visibility into service communication and behavior.Read 3 Oct 2026 · docs.cilium.io
Kubernetes support
The quick installation guide lists Kubernetes distributions and services including GKE, AKS, EKS, OpenShift, RKE, k3s, and Alibaba ACK.Read 3 Oct 2026 · docs.cilium.io
Networking
Its listed networking use cases include CNI, Layer 4 load balancing, Cluster Mesh, kube-proxy replacement, BGP, service mesh, Gateway API, IPv6, host firewall, and ingress.Read 3 Oct 2026 · cilium.io
Observability
Cilium lists service maps, metrics and tracing export, identity-aware L3/L4/DNS network flow logs, and advanced network protocol visibility.Read 3 Oct 2026 · cilium.io
Policy
Cilium network policies can enforce identity-aware rules at L3–L7, including DNS- and HTTP-aware filtering.Read 3 Oct 2026 · docs.cilium.io
Project status
Cilium identifies itself as a CNCF graduated project.Read 3 Oct 2026 · cilium.io
Scale limitation
The quick installation guide says environments larger than 500 nodes should refer to the Getting Started guide for large environments or specific datapath modes.Read 3 Oct 2026 · docs.cilium.io
Security features
Listed security capabilities include transparent encryption, network policy, and runtime security.Read 3 Oct 2026 · cilium.io
Security review
Cilium documentation links to 2022 security and fuzzing audits; the security audit summary reports no critical or high severity vulnerabilities found in that audit.Read 3 Oct 2026 · docs.cilium.io
System requirements
The 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.Read 3 Oct 2026 · docs.cilium.io

Plans and prices

Cilium Free Open source · Linux kernel >= 5.10 or equivalent · AMD64 and AArch64 Read 3 Oct 2026 · cilium.io

Every Cilium plan and price →

Strong points and limits

Strong points

  • Open source and free.
  • Policies can apply identity-aware rules through L7.
  • Hubble provides visibility into service communication.
  • Lists Prometheus and Grafana integrations.

Limits

  • Requires AMD64 or AArch64 Linux hosts.
  • Requires kernel 5.10 or later, or an equivalent.
  • Environments above 500 nodes need additional guidance.
  • ztunnel encryption support is marked beta.

Who it suits

Cilium suits teams managing workload networking who need policy, security, and observability capabilities in Linux environments. Its documented Kubernetes support covers several distributions and services.

Verdict

Cilium covers networking, security policy, and observability in one eBPF-powered system. Check the host kernel and scale guidance against the intended environment.

Where Specifiction places it

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