Namespaces in Kubernetes – Isolation, DNS,

🔍 What Happened?

Today, I was working with multiple namespaces in Kubernetes and ran into a small (but important) issue.
I had nginx pods running in:

• default namespace

• demo namespace (newly created)

Both were exposed using ClusterIP services.

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😤 The Problem

When I tried to access nginx from another namespace, it failed — not because of networking, but because the service name couldn't be resolved.

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🧠 Why?

In Kubernetes, each namespace has its own DNS scope.

So, when you try to access a service from a different namespace, you need to use a fully qualified domain name (FQDN) like:

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🛠️ The Fix

Once I used the FQDN, it worked perfectly!

Also verified all namespaces using:

I used the FQDN, it worked perfectly!

Also verified all namespaces using: kubectl get ns