# The Default Deny Dilemma: A Practical Guide to Kubernetes Network Policies

DevFeed: [The Default Deny Dilemma: A Practical Guide to Kubernetes Network Policies](<https://devfeed.tech/articles/the-default-deny-dilemma-a-practical-guide-to-kubernetes-network-policies-14493.md>)

Original publisher: [Read original article](<https://www.cybertec-postgresql.com/en/the-default-deny-dilemma-a-practical-guide-to-kubernetes-network-policies/>)

Author: Wellingtone Luvonga

Published: 2026-09-08T03:00:00Z

Content type: tutorial

Language: en

Sources: [CYBERTEC PostgreSQL | Services & Support](<https://devfeed.tech/sources/cybertec-postgresql-services-support.md>)

Topics: [Kubernetes](<https://devfeed.tech/topics/kubernetes.md>), [Network](<https://devfeed.tech/topics/network.md>), [Security](<https://devfeed.tech/topics/security.md>), [Zero Trust](<https://devfeed.tech/topics/zero-trust.md>), [Architecture & Design](<https://devfeed.tech/topics/architecture-design.md>)

Tags: [blog](<https://devfeed.tech/tags/blog.md>), [cni](<https://devfeed.tech/tags/cni.md>), [container](<https://devfeed.tech/tags/container.md>), [guide](<https://devfeed.tech/tags/guide.md>), [how-to](<https://devfeed.tech/tags/how-to.md>), [ingress](<https://devfeed.tech/tags/ingress.md>), [kubernetes](<https://devfeed.tech/tags/kubernetes.md>), [network](<https://devfeed.tech/tags/network.md>), [network-security](<https://devfeed.tech/tags/network-security.md>), [postgersql](<https://devfeed.tech/tags/postgersql.md>), [security](<https://devfeed.tech/tags/security.md>), [test](<https://devfeed.tech/tags/test.md>), [yaml](<https://devfeed.tech/tags/yaml.md>), [zero-trust](<https://devfeed.tech/tags/zero-trust.md>)

## AI overview

A hands-on lab for implementing zero-trust network segmentation in Kubernetes with NetworkPolicies. It demonstrates default-deny rules, label-based ingress and egress permissions, DNS access, external API restrictions, and traffic validation in a three-tier frontend, backend, and PostgreSQL architecture enforced by Calico.

## Source excerpt

This blog is a deep walkthrough about network policies in Kubernetes, read to know more. The post The Default Deny Dilemma: A Practical Guide to Kubernetes Network Policies appeared first on CYBERTEC PostgreSQL | Services & Support.