What you'll learn

By default, every pod in a Kubernetes cluster can talk to every other pod. That is a security problem. In this course, Certified Kubernetes Administrator (CKA): Network Policies and Traffic Management, you'll gain the ability to control, secure, and troubleshoot cluster networking at the pod level. First, you'll explore how pod networking works: the flat network model, CIDR ranges, CNI plugin responsibilities, and how kube-proxy and iptables route traffic between pods on different nodes. You'll trace a packet from source pod to destination pod to understand the full path. Next, you'll discover Network Policies for restricting pod-to-pod communication. You'll create ingress policies (who can talk to my pods) and egress policies (where my pods can send traffic), use label selectors and namespace selectors for targeting, and build a default-deny baseline that forces explicit allow rules for every communication path. Finally, you'll learn CoreDNS: how it resolves Service names to ClusterIPs, the DNS naming convention (..svc.cluster.local), how to troubleshoot DNS failures with nslookup and dig from inside pods, and how to customize CoreDNS with ConfigMap edits for stub domains and upstream forwarders. When you're finished with this course, you'll have the network security and DNS skills needed to control pod communication, enforce segmentation policies, and troubleshoot DNS on production Kubernetes clusters and handle every remaining Services and Networking task on the CKA exam.