What are Kubernetes Network Policies?

Kubernetes Network Policies are firewall rules at the pod level that control which traffic is allowed or blocked between pods. They are part of the security strategy in Kubernetes clusters and help minimize risks from unwanted communication.

How can Network Policies improve the security of my Kubernetes environment?

Network Policies enhance security by controlling traffic between pods and allowing only authorized connections. Implementing default deny policies significantly reduces the attack surface.

What best practices should I consider when implementing Network Policies?

Best practices include starting with a default deny policy, using namespace isolation for different environments, and allowing DNS access for egress traffic. Additionally, ensure that the CNI plugin you are using supports Network Policies.

What is the difference between Ingress and Egress Policies?

Ingress policies control which incoming traffic is allowed to a pod, while Egress policies regulate the outgoing traffic of a pod. Both types are essential for achieving comprehensive control over network traffic.

How do I implement Network Policies in my Kubernetes cluster?

To implement Network Policies, you need to define specific YAML files that contain the desired rules for pods and their communication. These files can then be applied in the cluster using kubectl. It is important to ensure that your cluster's CNI plugin supports these policies.

Zurück zu: Kubernetes Operations for SMEs

Kubernetes & Container 7 min. read

Kubernetes Network Policies: Microsegmentation for Container Workloads

By default, every pod in Kubernetes can communicate with every other pod. Network Policies change that — we show you how.

devRocks Engineering · 25. February 2026 · Aktualisiert: 31. March 2026 ·

Kubernetes Security Networking Calico

Kubernetes Network Policies: Microsegmentation for Container Workloads

The Problem: Flat Network

In a standard Kubernetes cluster, every pod can reach every other pod — regardless of the namespace. This is convenient for developers but a nightmare for security teams.

Understanding Network Policies

Network Policies are Kubernetes-native firewall rules at the pod level. They define which traffic is allowed — everything else is blocked (default deny).

Ingress Policies: Control incoming traffic — which pods are allowed to communicate with this pod?
Egress Policies: Control outgoing traffic — where is this pod allowed to establish connections?
Label-based: Policies select pods via labels, not IP addresses — dynamic and Kubernetes-native.

Best Practices

Default Deny: Start with a policy that blocks all traffic, then allow selectively.
Namespace Isolation: Separate environments (dev, staging, prod) at the namespace level with policies.
Allow DNS: Do not forget to allow egress to port 53 (DNS) — otherwise service discovery will stop working.
CNI Plugin: Ensure your CNI plugin supports Network Policies. Calico and Cilium are recommended.

Conclusion

Network Policies are a must for production Kubernetes clusters. They cost nothing, are declaratively manageable, and drastically reduce the attack surface. At devRocks, they are part of every cluster setup.