Kubernetes NetworkPolicy: A Hands-On Guide to Zero Trust Service Communication Control
A complete, practice-oriented guide to Kubernetes NetworkPolicy that closes security gaps in MSA environments at the root. It covers core principles, Ingress/Egress YAML implementation, and a Default Deny strategy based on least privilege.
Istio vs NetworkPolicy: Precedence When L3/L4 and L7 Policies Conflict
When service mesh adoption makes networking policy more complex, which rule actually wins if Istio and Kubernetes NetworkPolicy collide? This guide hierarchically analyzes L3/L4 vs. L7 policy precedence and presents practical architecture b
When a Kubernetes L7 Network Policy Doesn't Apply: An eBPF (Cilium) Debugging Workflow
When HTTP header-based L7 network policies fail in Kubernetes, simply re-applying them will not fix the problem. This guide analyzes eBPF vs. iptables, diagnoses three policy-failure pitfalls, and presents a practical debugging workflow usi
Resolving K8s NetworkPolicy Communication Errors: A Calico vs Cilium (iptables vs eBPF) Comparison Guide
This guide analyzes the root causes of NetworkPolicy failures by comparing how each CNI enforces policy (iptables vs eBPF). It then walks through a practical, step-by-step debugging workflow for capturing packets at the node level when Egre
Kubernetes Pod DNS Failure (CoreDNS) 5-Minute Diagnosis: can't resolve & Temporary failure
Classify Kubernetes Pod DNS failures—nslookup can't resolve and Temporary failure in name resolution—across CoreDNS, resolv.conf, ndots, and NetworkPolicy, then diagnose them with five copy-paste commands and per-cause fixes.
Kubernetes L4/L7 Security: A Guide to Combining Service Mesh and NetworkPolicy
Should you use L4 or L7 for security in a microservices environment? This post covers how NetworkPolicy and Service Mesh differ, plus the optimal combination strategy for defense in depth—complete with hands-on examples.
K8s NetworkPolicy Default Deny: A 3-Step Guide to Safe Adoption Without Service Disruption
A practical guide to minimizing service disruption risk when introducing Kubernetes NetworkPolicy and Default Deny. It covers a Calico vs. Cilium CNI comparison and a detailed 3-step safe adoption methodology based on logging mode.
K8s Communication Error Guide: 3-Step Troubleshooting from CNI to Service Mesh
A complete guide for when you hit Kubernetes networking issues such as Pod-to-Pod communication failures and Service discovery errors. It walks through a systematic 3-step troubleshooting roadmap—from CNI diagnostics through NetworkPolicy a
Implementing Zero Trust with K8s NetworkPolicy: Practical Ingress/Egress Traffic Control
Master NetworkPolicy, the core of Kubernetes internal network security. Go beyond the limits of default networking and learn how to build a least-privilege Zero Trust architecture—from Ingress/Egress control through production YAML examples