Linux Foundation Cilium-Associate Dumps Questions Answers

Technical explanation

The policy attaches an HTTP Layer 7 rule to port 80 but omits protocol: TCP from the associated ports entry. HTTP policy is layered on a Layer 4 TCP rule, and the documented Cilium form explicitly identifies TCP before specifying the HTTP method and path. D therefore identifies the configuration defect intended by the question.

The cross-namespace source selection is valid. The policy resides in namespace back and selects backend pods there. Its fromEndpoints selector explicitly includes k8s:io.kubernetes.pod.namespace: blog , allowing it to select matching app-frontend endpoints in that other namespace. Option A is consequently not an error.

The k8s: source prefix in k8s:app.kubernetes.io/name is also valid Cilium label syntax and identifies the Kubernetes label source, making B false. Port 80 may be used in a Cilium policy; the privileged-port restriction concerns which processes may bind low-numbered ports under operating-system permissions, not whether a network policy can reference them.

The corrected port entry should contain port: "80" together with protocol: TCP .

Official references

Cilium Layer 7 Policies , Kubernetes Constructs in Cilium Policy

Study Guide topic: Combining Layer 4 port rules with Layer 7 HTTP policies.

Technical explanation

The policy’s endpointSelector selects the ship workload in the namespace containing the CiliumNetworkPolicy , which is ns-cca . It also explicitly includes io.cilium.k8s.policy.cluster: cluster1 , confirming that the selected source endpoint belongs to cluster1.

The egress rule authorizes communication to an endpoint carrying name: base and the cluster label io.cilium.k8s.policy.cluster: cluster2 . Because the namespaced policy does not specify a different destination namespace through k8s:io.kubernetes.pod.namespace , the intended destination is the corresponding base workload in ns-cca on cluster2. Therefore, A matches the policy.

Options C and D incorrectly describe the rule as a deny rule. Cilium policy rules use an allow-list model unless an explicit egressDeny or ingressDeny section is present. The exhibit contains an ordinary egress rule, so matching traffic is authorized. Option B incorrectly places the destination in default .

Current Cilium versions require explicit cluster targeting for remote endpoints, which this policy provides through the cluster label.

Official references

Cluster Mesh Network Policy , Namespaces in Cilium Policy

Study Guide topic: Cluster Mesh labels, namespaced policies, and cross-cluster endpoint selection.

Technical explanation

If a global Service has no healthy local endpoints matching its selector, every available backend can be remote. Cluster Mesh synchronizes remote service and endpoint information, allowing the local Cilium datapath to load-balance requests to backend pods in connected clusters. The absence of local endpoints therefore provides a direct explanation for the observed behavior.

If the local cluster were not part of the Cluster Mesh, its Cilium agents would not normally receive the remote endpoint state needed to route traffic through the global Service, so B does not explain successful remote-only selection. An affinity value of none is the default behavior and expresses no preference between local and remote endpoints. When both categories exist and are healthy, this permits load balancing across both; it does not require every connection to use remote backends.

Setting service.cilium.io/shared: "false" prevents the local Service’s backends from being shared with remote clusters. It does not instruct the local cluster to direct all requests toward remote endpoints.

A separate possible cause, not presented among the choices, would be service.cilium.io/affinity: "remote" . Among the supplied answers, however, A is the valid explanation.

Official references

Service Affinity ; Cluster Mesh .

Study Guide topic: Cluster Mesh.