Cilium consulting and hands-on support

Cilium is a Kubernetes CNI that uses an eBPF-based datapath to deliver high-performance networking, identity-aware security policy enforcement, and built-in observability. It is commonly adopted by platform and DevOps teams to standardize service-to-service connectivity, apply consistent controls across microservices, and improve troubleshooting in fast-changing or multi-tenant clusters.

It typically runs as a DaemonSet on each node and integrates with Kubernetes primitives for policy management and traffic visibility; it can also support multi-cluster connectivity patterns as environments scale.

• eBPF-powered networking and efficient service load balancing in the datapath
• Support for Kubernetes NetworkPolicy plus extended identity-based policies
• Runtime flow visibility and logs to aid debugging and incident investigation
• Service-to-service encryption options for in-cluster traffic
• Multi-cluster connectivity and advanced routing capabilities

Cilium is a Kubernetes CNI that uses an eBPF-based datapath to provide high-performance networking, identity-aware security policy enforcement, and built-in observability. It is commonly used to reduce datapath overhead, apply consistent policy as workloads change, and speed up troubleshooting with flow-level visibility.

• eBPF-based packet processing reduces reliance on iptables, improving scalability and lowering tail latency on high-connection nodes.
• Identity-based policy ties enforcement to Kubernetes labels and workload identities, staying stable as pods churn and IPs change.
• Kubernetes NetworkPolicy compatibility supports incremental adoption without rewriting existing policy models.
• Extended policy with CiliumNetworkPolicy enables richer selectors and clusterwide patterns beyond baseline NetworkPolicy.
• Layer 7 policy for supported protocols enables application-aware controls such as restricting HTTP methods, paths, and DNS access.
• Hubble observability provides flow logs and service dependency mapping to accelerate root-cause analysis for drops, denies, and latency issues.
• Optional kube-proxy replacement and eBPF service load balancing can simplify the datapath and improve performance in large clusters.
• In-cluster encryption options such as WireGuard and IPsec help secure pod-to-pod traffic on untrusted or shared networks.
• Multi-cluster connectivity supports cross-cluster service communication with more consistent policy and visibility.
• Per-flow context reduces the need for node-level packet captures during incident response and networking debugging.

Cilium is a strong fit for production Kubernetes platforms that need higher throughput, deeper runtime visibility, or more expressive policy than a basic CNI plus NetworkPolicy typically provides. Key considerations include kernel and distribution compatibility, validating eBPF behavior across node images, and coordinating upgrades across Kubernetes, the kernel, and Cilium; details are covered in the Cilium documentation.

Common alternatives include Calico, Flannel, and Weave Net, with different trade-offs around policy depth, observability, and operational simplicity.

Our experience with Cilium helped us build practical knowledge, reusable runbooks, and automation patterns for strengthening Kubernetes networking, security, and observability with eBPF across production clusters.

Some of the things we did include:

• Implemented and standardized Cilium as the CNI for new and existing Kubernetes clusters, including migration planning from legacy CNIs with phased cutovers, validation gates, and rollback procedures.
• Designed and enforced least-privilege connectivity using Kubernetes NetworkPolicies and CiliumNetworkPolicies, translating application requirements into auditable policies with clear ownership and review workflows.
• Rolled out egress controls and guardrails (DNS-aware and L7 where appropriate), reducing risky outbound access while keeping developer experience predictable and debuggable.
• Enabled kube-proxy replacement and tuned datapath settings to reduce overhead and improve latency under load, validating results with repeatable benchmarks and canary rollouts.
• Configured Hubble for flow visibility, incident triage, and policy validation, and connected telemetry into Prometheus and Grafana dashboards for actionable SLOs.
• Hardened cluster networking with encryption-in-transit where required, including key rotation considerations and performance impact analysis for different traffic profiles.
• Implemented ingress and traffic management patterns alongside Istio in environments that needed both service mesh features and kernel-level enforcement.
• Automated installation, upgrades, and configuration drift detection using GitOps practices with Argo CD, including environment overlays, version pinning, and safe upgrade runbooks.
• Validated multi-tenant and multi-namespace isolation models, documenting allowed flows and exception handling to support audits and reduce “tribal knowledge” dependencies.
• Built day-2 operational playbooks for common failure modes (policy regressions, node churn, MTU issues, conntrack pressure) and trained platform teams on safe operations and troubleshooting.

This experience helped us accumulate significant knowledge across multiple Cilium use-cases—migration, policy enforcement, observability, performance tuning, and day-2 operations—and enables us to deliver high-quality Cilium setups that are maintainable, measurable, and reliable in real production environments.

Some of the things we can help you do with Cilium include:

• Assess your current Kubernetes networking and security posture and deliver a prioritized report covering datapath behavior, policy coverage, observability gaps, and operational risk.
• Define a pragmatic adoption roadmap for rolling out eBPF-based networking across clusters with milestones, rollout/rollback patterns, and success criteria.
• Implement and configure Cilium on new or existing clusters, including migration planning from legacy CNIs and safe cutover procedures.
• Design and enforce least-privilege network guardrails with Kubernetes NetworkPolicies and Cilium features to support compliance, segmentation, and reduced blast radius.
• Automate Cilium installation, configuration, and policy delivery using IaC and GitOps workflows (e.g., Terraform and Argo CD) for versioned, repeatable changes.
• Set up flow-level observability for drops, DNS, and latency, and align dashboards/alerts to SLOs and incident response runbooks.
• Optimize performance and cost by tuning datapath settings, reducing noisy east-west traffic, and validating MTU, conntrack, and kube-proxy replacement choices.
• Troubleshoot intermittent connectivity, service-to-service communication, and DNS issues using eBPF-driven visibility to shorten MTTR.
• Harden day-2 operations with upgrade strategies, compatibility checks, rollback plans, and reusable runbooks for multi-environment reliability.
• Enable your teams with hands-on training and documentation for policy authoring, troubleshooting workflows, and ongoing Cilium operations.