EX280 Networking And Network Policies Practice Test 3 — 15 Questions

Question 1

An administrator needs to delete a Service named 'old-service' in the 'test' namespace. Which command accomplishes this?

Accepted Answer

oc delete service old-service -n test. The oc delete service command removes the specified service resource.

Answer

oc remove svc old-service --namespace=test

Answer

oc prune service old-service -n test

Answer

oc destroy service old-service -n test

Question 2

An administrator needs to configure a Route that handles encrypted communication both from the client to the router AND from the router to the backend pod. Which termination type is required?

Accepted Answer

reencrypt. Re-encrypt termination decrypts TLS at the router and then re-encrypts a new TLS connection to the backend pod.

Answer

passthrough

Answer

edge

Answer

secure-tunnel

Question 3

An administrator wants to check the status of all cluster operators, specifically verifying that the Network and DNS operators are healthy. Which command should be run?

Accepted Answer

oc get clusteroperators. The oc get clusteroperators command lists all cluster operators and their availability/health status.

Answer

oc get operators --cluster

Answer

oc describe operators

Answer

oc adm check health

Question 4

An administrator observes that pods in a specific namespace are unable to resolve external domain names (e.g., www.redhat.com) while internal service resolution works perfectly. What is the most likely cause of this issue in CoreDNS configuration?

Accepted Answer

The Corefile in the cluster DNS operator configuration has incorrect or missing forward plugins for external resolvers.. CoreDNS forwards external queries to upstream forwarders (like corporate DNS or public resolvers). If the forwarding block in the Corefile is misconfigured, external resolution fails.

Answer

The API server service is missing endpoint IPs.

Answer

NodePort range exhaustion prevents external DNS packets from traversing worker nodes.

Answer

The cluster ingress controller is blocking external UDP port 53.

Question 5

Which TWO fields are mandatory when defining a standard Kubernetes NetworkPolicy object? (Choose TWO)

Accepted Answer

metadata. A NetworkPolicy requires 'apiVersion', 'kind', 'metadata', and 'spec' (with podSelector). From the specific choices, spec.podSelector and metadata are essential.

Answer

spec.ingress

Answer

spec.egress.to.ipBlock

Answer

metadata.namespace

Question 6

Which TWO of the following are valid Service types supported natively in OpenShift? (Choose TWO)

Accepted Answer

ClusterIP. ClusterIP, NodePort, and LoadBalancer are standard Kubernetes/OpenShift service types. (ExternalName is also valid, Route is not a service type).

Answer

VirtualIP

Answer

IngressObject

Answer

Route

Question 7

Which THREE commands can an administrator use to inspect existing routes in an OpenShift cluster? (Choose THREE)

Accepted Answer

oc get routes. oc get routes, oc describe route, and oc get route are standard commands. (oc explain route is also valid for documentation). Let's select get, describe, and explain.

Answer

oc top route

Answer

oc logs route/<route-name>

Question 8

Which THREE of the following components are part of the standard OpenShift Ingress architecture? (Choose THREE)

Accepted Answer

IngressController Custom Resource. The Ingress operator, router pods (HAProxy-based), and IngressController custom resources form the core OpenShift Ingress stack.

Answer

ClusterNetwork operator

Answer

EgressFirewall controller

Question 9

Which TWO options describe characteristics of OVN-Kubernetes compared to the legacy OpenShift SDN? (Choose TWO)

Accepted Answer

It provides native support for EgressIP and EgressFirewall custom resources.. OVN-Kubernetes is the default CNI in OpenShift 4.12+ (and 4.14+), provides native support for EgressIP, and uses OVS flow tables.

Answer

It relies exclusively on traditional Linux iptables rules without OVS flow tables.

Answer

It requires the flannel CNI plugin to function.

Answer

It does not support NetworkPolicies.

Question 10

Which THREE troubleshooting steps should an administrator take when a newly created Route fails to resolve or connect? (Choose THREE)

Accepted Answer

Check that the Route hostname resolves correctly via DNS to the cluster router IP.. Checking service endpoints, verifying route hostname DNS resolution externally, and checking Ingress controller/router logs are crucial troubleshooting steps.

Answer

Reinstall the entire cluster storage operator.

Answer

Modify the cluster kube-apiserver certificates.

Question 11

Which TWO tools or protocols can an administrator use to verify internal cluster DNS resolution from a pod? (Choose TWO)

Accepted Answer

nslookup. nslookup and dig are standard tools for DNS queries.

Answer

ping

Answer

ifconfig

Answer

top

Question 12

Which TWO commands are used to check the health and status of the cluster networking operator? (Choose TWO)

Accepted Answer

oc describe clusteroperator network. oc get clusteroperators and oc describe clusteroperator network are correct.

Answer

oc get routes --all-nodes

Answer

oc adm network status

Answer

oc top network

Question 13

Which THREE actions can be performed using the IngressController custom resource? (Choose THREE)

Accepted Answer

Scaling the number of router replicas.. IngressController allows configuring replica counts, setting default TLS certificates, and choosing endpoint publishing strategies.

Answer

Modifying the core Kubernetes API server port.

Answer

Defining the container security context constraints for worker nodes.

Question 14

Which THREE network-related objects are namespaced in OpenShift? (Choose THREE)

Accepted Answer

NetworkPolicy. Services, Routes, and NetworkPolicies are namespaced resources, whereas IngressControllers and ClusterNetworks are cluster-scoped.

Answer

ClusterNetwork

Answer

IngressController

Question 15

Which THREE parameters can be configured within the cluster DNS operator resource (dns.operator/default)? (Choose THREE)

Accepted Answer

Upstream DNS forwarders. The DNS operator allows configuring forwarders, client IP handling, and server blocks/zones.

Answer

The physical MTU size of the cluster worker node network interfaces

Answer

The default HAProxy router replica count