Cilium-Associate Exam Dumps - Cilium Certified AssociateCCA

Technical explanation

Cilium tunnel mode supports VXLAN and Geneve encapsulation. In this routing model, Cilium nodes form an overlay mesh, and traffic exchanged between nodes is carried inside UDP-encapsulated packets. VXLAN is the default tunnel protocol and normally uses UDP port 8472. Geneve is the alternative and normally uses UDP port 6081. Operators select the protocol through the tunnel-protocol configuration setting, whose documented values are vxlan and geneve .

Encapsulation reduces the requirements placed on the underlying network. The underlay only needs to provide IP connectivity between the Kubernetes nodes and permit the selected UDP tunnel port. It does not need to learn or route individual PodCIDRs. Cilium also uses the tunnel metadata to carry information such as the source security identity, avoiding an additional identity lookup on the receiving node.

MPLS, OTV, STT, and EVPN are not supported values for Cilium’s tunnel-protocol setting. EVPN may be used in broader data-center network designs, and MPLS is a carrier-routing technology, but neither is a Cilium overlay encapsulation choice. Therefore, B is the only supported pair.

Official references

Cilium Routing ; System Requirements .

Study Guide topic: Architecture.

Technical explanation

The status output shows Envoy DaemonSet: disabled (using embedded mode) . In embedded mode, Cilium starts Envoy as a separate process inside the Cilium agent pod when a feature requiring Layer 7 processing—such as an L7 network policy, protocol visibility, Ingress, or Gateway API—is used. This is precisely the behavior described in option B.

The remaining choices contradict the exhibit. The Cilium DaemonSet has a desired count of three, which ordinarily indicates three schedulable nodes running Cilium, not four. Hubble Relay: OK means the aggregation component is healthy. Hubble Relay connects to the Hubble instances associated with Cilium agents and presents a multi-node API to clients such as Hubble CLI and Hubble UI. Finally, ClusterMesh: disabled rules out the claim that the installation is currently configured for Cilium Cluster Mesh service discovery and cross-cluster load balancing.

Cilium can alternatively run Envoy through the independently life-cycled cilium-envoy DaemonSet. That is not the deployment displayed here because the DaemonSet is explicitly disabled and embedded mode is reported.

Official references

Envoy deployment modes ; Hubble internals .

Study Guide topic: Architecture.

Technical explanation

C accurately describes eBPF host-routing. In a conventional datapath, packets may traverse substantial portions of the host networking stack and its iptables hooks even when Cilium performs routing decisions with eBPF. eBPF host-routing takes a more direct datapath, bypassing iptables and the upper host stack while providing a faster transition between the host and pod network namespaces. This reduces processing and context-switching overhead and can improve throughput and latency.

Option A describes load-balancing behavior rather than host routing. Backend distribution is implemented through Cilium’s service load-balancer maps and algorithms. Host routing can improve the path used by resulting packets, but it does not itself guarantee even backend selection.

Option B is the description of BIG TCP. BIG TCP increases the size of internal GSO and GRO packets to reduce stack traversal. Although BIG TCP requires eBPF host-routing in supported Cilium configurations, the two are distinct features.

Option D is overly specific and does not define the feature. Host routing optimizes compatible pod traffic generally, subject to kernel, kube-proxy-replacement, masquerading, netfilter, encryption, and integration constraints.

Official references

Cilium eBPF Host-Routing

Study Guide topic: eBPF host-routing, host-stack bypass, veth traversal, and performance.

Technical explanation

The intended answer is A because API request limiting corresponds to rate limiting, which Cilium identifies as a core Layer 7 traffic-management capability. Cilium combines its eBPF datapath with Envoy for application-layer processing. The official Service Mesh documentation expressly includes rate limiting among the functions that must understand protocols such as HTTP, REST, gRPC, and WebSocket. It is therefore not merely packet-rate policing at Layer 3 or Layer 4; it can be applied with application-protocol context.

However, this question is no longer valid as a strict single-answer item. Current Cilium documentation also describes proxy-based Layer 7 load balancing as useful for gRPC and provides an Envoy-backed implementation for Kubernetes Services. Consequently, option C is also supportable under the current product documentation, although the feature is identified as beta. API authorization and fault-delay injection are not presented as equivalent first-class Cilium Service Mesh use cases in the cited feature overview.

For certification-bank purposes, retain A as the intended answer, but revise option C or qualify it to restore a unique correct choice.

Official references

Service Mesh ; Proxy Load Balancing for Kubernetes Services .

Study Guide topic: Service Mesh.

Technical explanation

Option B correctly represents the Ingress as a Gateway and an attached HTTPRoute . The Gateway is named cilium , uses gatewayClassName: cilium , and exposes an HTTP listener on port 80. The HTTPRoute uses parentRefs with the same Gateway name, cilium , so the route attaches to the declared listener. Its two rules preserve the original routing behavior: /details with PathPrefix targets the details Service on port 9080, while / with PathPrefix targets productpage on port 9080.

Option A declares a Gateway named cilium but attaches its route to nginx-gateway . Because the parent reference does not identify the displayed Gateway, it is not equivalent. Options C and D use kind: Route ; the correct resource kind for HTTP path routing is HTTPRoute . They also contain malformed or altered backend and matching fields. Option D changes the details backend name, while option C contains incorrect route structure and path content.

Cilium’s official migration example uses the same conversion pattern: the Ingress class becomes the Gateway’s class, paths move into HTTPRoute.rules , and the route identifies its Gateway through parentRefs .

The supplied key incorrectly identifies A. The verified answer is B.

Official references

HTTP Migration Example .

Study Guide topic: Service Mesh.