10 CCA questions with full explanations for every option, free to view on this page.
Installation and Configuration
Q1. When you run 'cilium connectivity test', what does it verify about the cluster?
Reveal answer and explanations
AOnly DNS resolution
Incorrect. DNS is tested but not the sole focus.
BWhether all pods can reach the Kubernetes API server
Incorrect. Connectivity test is broader than API server access.
CPod-to-pod connectivity across all supported traffic patterns (ingress, egress, L7)
Correct. The connectivity test validates pod-to-pod traffic in multiple directions and protocols.
DKubernetes node-to-node connectivity only
Incorrect. Node connectivity is network infrastructure; the test focuses on pod networking.
Cluster Mesh
Q2. In ClusterMesh, a service is annotated with 'io.cilium.service/global: true'. What does this enable?
Reveal answer and explanations
AThe service is accessible cluster-wide with the same cluster-local IP address
Incorrect. ClusterIP addresses are cluster-local; they can't be shared across clusters.
BThe service's endpoints are distributed across all connected clusters for load balancing
Incorrect. Endpoints aren't distributed; the service stays in its origin cluster with all endpoints there.
CThe service is replicated to all connected clusters with the same name and namespace
Incorrect. The service isn't replicated; it remains in its original cluster.
DThe service is advertised to all connected clusters; pods in remote clusters can access it using its FQDN
Correct. Global services are advertised to all connected clusters; remote pods can resolve and access them via FQDN (e.g., 'service.namespace.svc.clustermesh.local').
Service Mesh
Q3. What is the primary architectural advantage of Cilium's sidecarless service mesh approach over traditional sidecar-based service meshes?
Reveal answer and explanations
AReduces per-pod resource overhead by implementing networking in the kernel via eBPF instead of a sidecar container
Correct. Cilium uses eBPF-based sidecarless service mesh to avoid the memory and CPU overhead of per-pod sidecar containers.
BEliminates the need for load balancing
Incorrect. Load balancing is still required and performed at the kernel level.
CProvides better application performance through sidecar optimization
Incorrect. Sidecarless approach provides better efficiency, not traditional sidecars.
DAutomatically handles multi-cluster communication
Incorrect. Multi-cluster support is through ClusterMesh, separate from the sidecar choice.
Service Mesh
Q4. In Cilium's Gateway API implementation, what does a ReferenceGrant resource accomplish?
Reveal answer and explanations
AIt authorizes a Gateway in one namespace to reference a Service in a different namespace
Correct. ReferenceGrant is a Gateway API resource that permits a Gateway in namespace A to reference a Service in namespace B, preventing unauthorized cross-namespace access.
BIt creates a temporary tunnel between namespaces for service-to-service traffic
Incorrect. ReferenceGrant doesn't create tunnels; it authorizes API references only.
CIt grants permissions for cross-cluster service mesh communication via ClusterMesh
Incorrect. ClusterMesh uses different CRDs (GlobalService, ClusterMeshService) for cross-cluster authorization.
DIt allows a pod to bypass mTLS when communicating with a gateway
Incorrect. ReferenceGrant doesn't affect mTLS enforcement; it's an authorization mechanism.
Network Observability
Q5. When you enable Hubble metrics export to Prometheus, which of the following metrics are typically available?
Reveal answer and explanations
AOnly flow rate and packet counts
Incorrect. Multiple metric categories are available.
BCilium-agent daemon status metrics only
Incorrect. Hubble exports network flow metrics, not daemon status.
CFlow metrics, HTTP-specific metrics, and DNS-specific metrics based on enabled protocols
Correct. Hubble exports protocol-agnostic and protocol-specific metrics (HTTP, DNS, gRPC, etc.) to Prometheus.
DPod CPU and memory usage
Incorrect. Resource metrics are not Hubble's responsibility.
Installation and Configuration
Q6. You run 'cilium-dbg privileged get-identity labels k8s:app=prod'. The command fails with 'endpoint not found'. What does this indicate?
Reveal answer and explanations
AThe label selector syntax is incorrect; use 'k8s.app=prod' instead
Incorrect. The label syntax 'k8s:app=prod' is correct.
BThe get-identity command doesn't support label-based queries; use 'cilium identity list' instead
Incorrect. get-identity does support label-based queries.
CNo pod with label 'app=prod' currently exists in the cluster
Correct. The 'endpoint not found' error means no pod matches the specified label in the cluster at that moment.
DThe cilium-agent hasn't finished syncing identities from the operator
Incorrect. Sync issues would affect all identity queries, not just this label.
Installation and Configuration
Q7. After modifying Cilium configuration through Helm values, what command allows you to view the current active configuration without redeploying?
Reveal answer and explanations
Akubectl get configmap cilium-config
Incorrect. The ConfigMap is one representation, but 'cilium config view' is the CLI tool.
Bcilium status --verbose
Incorrect. 'cilium status --verbose' reports status details, but it is not the focused command for viewing active configuration values.
Ccilium-agent --print-config
Incorrect. This is not a valid cilium-agent option.
Dcilium config view
Correct. 'cilium config view' displays the currently active Cilium configuration.
Cluster Mesh
Q8. A global service in ClusterMesh cluster-1 has 10 endpoints, but traffic from cluster-2 pods shows 70% packet loss. The clusters are directly connected via a dedicated network link. What is the most likely cause?
Reveal answer and explanations
AThe ClusterMesh egress gateway is filtering traffic from cluster-2; check the egress rules
Incorrect. ClusterMesh doesn't use egress gateways for inter-cluster service traffic.
BThe clustermesh-apiserver in cluster-1 is overloaded and dropping endpoint updates
Correct. High packet loss to remote service endpoints typically indicates the clustermesh-apiserver isn't reliably distributing endpoint updates, causing stale or partial endpoint knowledge.
CCross-cluster service traffic is being routed through a misconfigured pod CIDR overlap that causes asymmetric routing
Incorrect. CIDR overlap would be caught during ClusterMesh setup; setup validation prevents this.
DService affinity is set to 'local', causing cluster-2 to fail over to cluster-1's endpoints with high latency
Incorrect. Service affinity set to 'local' would completely fail over, not cause 70% loss.
Service Mesh
Q9. When using Cilium's Gateway API implementation, what does a 'HTTPRoute' resource specifically define?
Reveal answer and explanations
AHTTP protocol version requirements
Incorrect. HTTP version is part of routing context but not HTTPRoute's primary purpose.
BMapping of HTTP requests to backend services with path/host matching and traffic splitting
Correct. HTTPRoute defines how HTTP requests are routed to backend services based on hostname, path, and headers.
CDNS resolution rules for gateways
Incorrect. DNS is separate from routing definitions.
DSSL/TLS certificate configuration
Incorrect. TLS is handled by TLSRoute, not HTTPRoute.
Service Mesh
Q10. A TLSRoute in Cilium's Gateway API specifies: ```yaml
passthrough: true
``` What happens to TLS termination and SNI routing?
Reveal answer and explanations
AThe gateway terminates TLS and reroutes based on the decrypted SNI header
Incorrect. Passthrough mode doesn't terminate TLS; it avoids decryption.
BPassthrough mode disables all TLS validation; traffic is routed without encryption
Incorrect. Passthrough mode preserves TLS encryption; it doesn't disable validation.
CTLS is not terminated; the encrypted traffic is proxied directly to backends, with SNI-based routing preserved
Correct. In passthrough mode, the gateway proxies encrypted TLS traffic directly to backends without terminating, preserving SNI information for backend routing decisions.
DThe gateway requires SNI to be decrypted, but TLS renegotiation happens at the backend
Incorrect. Passthrough doesn't terminate; SNI remains encrypted in the TLS ClientHello.
These questions are written against the current CCA curriculum — not scraped exam dumps. The full CCA library here has 120 questions; the broader platform covers the rest of the Golden Kubestronaut path.