CKAD Services and Networking Practice Question
A Service of type LoadBalancer is created but the external IP remains pending. What is the most likely reason?
⚠ Common exam trap
A common pitfall in CKAD is assuming that a Service of type LoadBalancer will automatically get an external IP in any Kubernetes cluster. In reality, Kubernetes relies on an external load balancer controller (e.g., cloud-controller-manager or a bare-metal solution like MetalLB) to provision the IP. Without such a controller, the external IP remains pending.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The cluster does not have a load balancer controller
A Service of type LoadBalancer in Kubernetes requires an external load balancer controller (e.g., cloud-controller-manager for AWS, Azure, GCP, or MetalLB for on-premises) to provision and assign the external IP. If no such controller is running in the cluster, the external IP remains in 'pending' state indefinitely because Kubernetes itself does not implement load balancer logic. This is the most common reason for a stuck pending external IP.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The service selector does not match any pods
Why it's wrong here
A mismatch between the service selector and pod labels results in empty endpoints, meaning the service has no backing pods to receive traffic. However, the cloud controller (or load balancer controller) provisions the external load balancer and assigns an external IP independently of whether endpoints exist. If a load balancer is successfully provisioned, the service would still receive an external IP, so the pending state is not caused by selector mismatch.
- ✗
The service port is already in use
Why it's wrong here
If the service port is already allocated to another service on the same IP, Kubernetes will emit an error event and the service creation or update will fail. A port conflict is a validation or runtime error that is reported immediately, not something that leaves the service in a pending state waiting for an external IP. The external IP population is tied to the load balancer provisioning process, not to port availability.
- ✓
The cluster does not have a load balancer controller
Why this is correct
Without a load balancer controller running in the cluster, there is no controller-manager component to detect the LoadBalancer service and create the actual load balancer resource in the cloud provider. Consequently, the service's status field for load balancer ingress remains unset and the external IP stays stuck at '<pending>' indefinitely. This is the standard symptom when a cluster is misconfigured or running on bare metal without a controller like MetalLB.
- ✗
The namespace has a NetworkPolicy blocking traffic
Why it's wrong here
NetworkPolicies operate at the pod network level, filtering traffic between pods based on labels and ports; they do not affect how Kubernetes provisions infrastructure. The load balancer controller and cloud provider APIs handle the creation of the external load balancer and the assignment of its IP, which is entirely outside the data path governed by NetworkPolicy. Thus, a NetworkPolicy could block traffic to the pods after the service is created but cannot prevent the external IP from being assigned.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CKAD practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CKAD exam.