Production Kubernetes networking failures follow predictable patterns. This guide provides a systematic approach to diagnosing common issues using a layered methodology: Ingress → Service → Endpoints → Pod → Container. The most common production failure is a ClusterIP Service with empty endpoints, typically caused by label selector mismatches between the Service and Pod templates.

When troubleshooting, always verify endpoints first using 'kubectl get endpoints <service-name>' - if empty, check selectors and readiness probes. NodePort services pose security risks by exposing every node and should be avoided in production; use ClusterIP with Ingress or LoadBalancer instead. LoadBalancer services often fail due to cloud provider health check mismatches or security group restrictions.

Ingress 404 errors usually indicate incorrect backend service names or port definitions. DNS failures stem from CoreDNS issues or namespace mismatches. The key principle is methodical layer-by-layer verification rather than random debugging.

For production traffic, the standard pattern is ClusterIP services behind an Ingress controller for routing, TLS termination, and cost efficiency. This approach provides observability, security, and scalability while avoiding the pitfalls of direct node exposure.