MultiHub Forum

My team is migrating our legacy monolithic application to a microservices architecture, and we've decided to use Kubernetes for orchestration, but we're hitting a wall with designing an efficient networking model. We're struggling to choose between different CNI plugins and understand how to properly configure network policies for inter-service communication while maintaining security. For engineers who have managed production Kubernetes clusters, what are the key considerations and potential pitfalls when setting up networking for a multi-tenant environment? How do you balance performance with security isolation, and what monitoring tools have you found most effective for diagnosing network-related issues like latency or packet loss between pods across different nodes?

Two top CNIs for production multi-tenant clusters are Calico and Cilium. If you want straightforward policy, Calico is a safe starting point; if you want deep observability and kernel-level enforcement, go with Cilium (eBPF). Either way, plan to run with a default-deny posture and add allow rules per namespace/service. Start by picking one CNI, spin up a staging cluster, and define a minimal policy per tenant (namespaces) before onboarding workloads.