CKA Services and Networking Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  ExternalName

  Why it's wrong here

  ExternalName is a special service type that does not use selectors or define ports. Instead, it acts as a local alias by returning a CNAME record pointing to an external DNS name, such as an external database endpoint. Because it operates purely at the DNS level within CoreDNS, it does not allocate cluster IPs or expose any ports on the cluster nodes themselves.

• ✗

  ClusterIP

  Why it's wrong here

  ClusterIP is the default Kubernetes service type that allocates a stable, internal IP address from the cluster's private network range. This IP is only reachable from within the cluster itself, making it unsuitable for direct external access. It does not bind to or expose any ports on the host interfaces of the cluster's physical or virtual nodes.

• ✗

  LoadBalancer

  Why it's wrong here

  LoadBalancer relies on cloud provider integrations to provision an external load balancer that routes incoming traffic to the cluster. While it implicitly configures NodePorts under the hood to route traffic from the load balancer to the pods, the primary mechanism of exposure is the external IP address assigned by the cloud provider, rather than exposing the service directly on node IPs for client consumption.

• ✓

  NodePort

  Why this is correct

  A NodePort Service allocates a static port from the default range 30000–32767 on every node’s IP address, forwarding inbound traffic on that port to the Service’s ClusterIP and then to the selected Pods. This satisfies the stem’s constraint of exposing the Service on a static port per node IP, unlike ClusterIP (internal only) or LoadBalancer (cloud-provisioned external IP).

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