CCNA Istio Installation Upgrade And Configuration Questions

MCQhard

You want to exclude a specific container in a pod from being injected with the Istio proxy. How is this achieved?

A.Modify the IstioOperator to exclude the container

B.Add label 'sidecar.istio.io/skip'

C.Add annotation 'sidecar.istio.io/inject: "false"' to the pod

D.Add environment variable 'ISTIO_PROXY_IGNORE=true'

AnswerC

This tells the injector to ignore the pod.

Why this answer

You add the annotation 'sidecar.istio.io/inject: "false"' to the pod template or the specific container annotation if supported via sidecar lifecycle hooks.

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MCQhard

You are performing an in-place upgrade of Istio. You have updated the control plane, but your data plane proxies are still running the old image. What is the standard process to upgrade the proxies?

A.istioctl upgrade --data-plane

B.kubectl rollout restart deployment

C.kubectl patch deployment -p '{"spec":{"template":{"metadata":{"annotations":{"sidecar.istio.io/status":"update"}}}}}'

D.istioctl proxy-status --upgrade

AnswerB

Rolling restart is required to re-inject the updated sidecar proxy.

Why this answer

To upgrade the data plane proxies, you must perform a rolling restart of the pods to trigger the injector to pull the new sidecar image.

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MCQmedium

If you want to use a custom proxy image for your sidecars, where should this be specified in the IstioOperator configuration?

A.spec.components.proxy.image

B.spec.meshConfig.defaultConfig.proxyImage

C.spec.sidecarInjector.image

D.spec.values.global.proxy.image

AnswerD

This is the correct path to override the image.

Why this answer

The 'spec.values.global.proxy.image' field is used to override the default image for the sidecar proxies.

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MCQeasy

Which profile is recommended for a production environment where high availability and performance are required?

A.minimal

B.empty

C.default

D.demo

AnswerC

Default profile provides production-ready configuration.

Why this answer

The 'default' profile is optimized for production use cases with HA settings enabled.

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MCQmedium

When using IstioOperator to customize the installation, you want to change the number of replicas for the Istiod control plane. Where should this be defined?

A.spec.values.pilot.scaling

B.spec.meshConfig.pilot.replicas

C.spec.pilot.replicas

D.spec.components.pilot.k8s.replicaCount

AnswerD

This field directly controls the replica count for the pilot component.

Why this answer

The 'spec.components.pilot.k8s.hpaSpec' or 'spec.components.pilot.k8s.replicaCount' fields are the correct places to define scale for the pilot component.

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MCQeasy

What is the purpose of the 'istio-sidecar-injector' service in the Istio control plane?

A.To inject the Envoy proxy sidecar into pods

B.To act as a load balancer for traffic

C.To monitor the health of pods

D.To store mesh configuration data

AnswerA

This is the primary function of the injector.

Why this answer

The sidecar injector is a MutatingAdmissionWebhook that intercepts pod creation requests to inject the proxy container.

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Multi-Selectmedium

Which TWO fields in the IstioOperator CR are commonly used to configure ingress gateway resources?

Select 2 answers

A.spec.gateways.enabled

B.spec.components.ingressGateways

C.spec.values.gateways.istio-ingressgateway

D.spec.pilot.gateways

E.spec.meshConfig.ingress

AnswersB, C

Main location for component definition.

Why this answer

The 'spec.components.ingressGateways' and 'spec.values.gateways.istio-ingressgateway' are the standard configuration areas for gateway resources.

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MCQeasy

Which 'istioctl' command is used to verify that the current Istio configuration in a cluster is valid and follows best practices?

A.istioctl analyze

B.istioctl check

C.istioctl diagnose

D.istioctl verify

AnswerA

This is the correct command for diagnostic analysis.

Why this answer

The 'istioctl analyze' command inspects the cluster and identifies configuration errors or warnings.

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Multi-Selectmedium

Which TWO Istio components can be configured via the 'spec.components' section in IstioOperator?

Select 2 answers

A.pilot

B.ingressGateways

C.prometheus

D.kiali

E.jaeger

AnswersA, B

Istiod is a core component.

Why this answer

Both 'pilot' (the core control plane) and 'ingressGateways' are core components configurable under 'spec.components'.

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Multi-Selecthard

When planning an Istio upgrade, which THREE steps are critical for a canary upgrade strategy?

Select 3 answers

A.Install the new version as a separate revision

B.Update the 'istio.io/rev' label on the target namespace

C.Perform an in-place upgrade of the existing istiod

D.Delete the old IstioOperator CR

E.Restart the application pods in the namespace

AnswersA, B, E

Required for parallel control planes.

Why this answer

Canary upgrades require installing a new revision, updating the namespace label, and then performing a rolling restart of the application pods.

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Multi-Selecthard

Which THREE actions occur when you label a namespace with 'istio-injection=enabled'?

Select 3 answers

A.New pods created in the namespace are injected with a sidecar

B.The mutation webhook is configured to watch this namespace

C.The istiod deployment is scaled up

D.The sidecar injector webhook adds the proxy container to new pods

E.All existing pods are immediately restarted

AnswersA, B, D

This is the primary function.

Why this answer

The webhook controller is notified, existing pods are not affected, but new pods will have the sidecar injected automatically.

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MCQhard

You have a cluster with multiple revisions of Istio installed. You want to move a namespace from revision '1-18' to '1-19'. What is the correct procedure?

A.Use 'istioctl install --revision 1-19' on the namespace

B.Update label and restart pods

C.Update label and run 'istioctl proxy-config rev 1-19'

D.Just update the label; Istio handles it automatically

AnswerB

Updating the label and restarting the pods forces the injector to use the new sidecar version.

Why this answer

You must update the 'istio.io/rev' label on the namespace to the new revision and then perform a rolling restart of the pods in that namespace.

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MCQmedium

When configuring an IstioOperator file, what does the 'spec.meshConfig' section primarily control?

A.Mesh-wide proxy and traffic behavior policies

B.The version of Istio to install

C.The ingress gateway load balancer IP

D.Kubernetes deployment manifests for Istiod

AnswerA

This is the primary purpose of meshConfig.

Why this answer

The 'meshConfig' section defines the mesh-wide configuration options that apply to all proxies in the mesh.

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Multi-Selecteasy

Which THREE commands can be used to manage or inspect the Istio mesh configuration?

Select 3 answers

A.istioctl version

B.istioctl proxy-config

C.istioctl analyze

D.istioctl deploy

E.istioctl upgrade

AnswersA, B, C

Command exists to check versions.

Why this answer

The 'istioctl' tool provides 'analyze', 'proxy-config', and 'version' commands for mesh inspection and management.

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Multi-Selectmedium

Which TWO of the following are valid ways to verify the status of an Istio control plane deployment?

Select 2 answers

A.istioctl verify-install

B.kubectl get deploy istiod -n istio-system

C.istioctl proxy-status

D.istioctl mesh-check

E.kubectl describe ingressgateway

AnswersA, B

Valid command to verify control plane health.

Why this answer

Using 'istioctl verify-install' checks the health of the control plane, and checking the status of the 'istiod' deployment via kubectl is a standard Kubernetes verification method.

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MCQeasy

A team wants to enable sidecar injection for a specific namespace without modifying the deployment manifests. What is the most efficient way to achieve this?

A.istioctl inject -n <namespace>

B.kubectl apply -f sidecar-injector.yaml

C.kubectl label namespace <name> istio-injection=enabled

D.kubectl annotate namespace <name> istio-injection=enabled

AnswerC

Labels are the standard way to trigger injection.

Why this answer

Labeling the namespace with 'istio-injection=enabled' triggers the sidecar injector webhook to automatically inject proxies into new pods.

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MCQmedium

You are performing a canary upgrade of the Istio control plane using the revision-based approach. After deploying the new revision, how do you verify which pods are currently pointing to the new control plane?

A.istioctl upgrade status

B.istioctl proxy-config endpoint

C.kubectl describe svc istiod

D.kubectl get pods -l istio.io/rev

AnswerD

This identifies pods associated with specific revisions.

Why this answer

You verify the configuration by checking the 'istio.io/rev' label on the pods to see which revision they are assigned to.

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MCQmedium

You are debugging an Istio installation issue. Which command allows you to view the currently applied IstioOperator configuration in the cluster?

A.istioctl manifest get

B.kubectl get istiooperator -n istio-system

C.helm get values istio

D.istioctl config dump

AnswerB

This displays the applied IstioOperator CR.

Why this answer

The 'kubectl get istiooperator -n istio-system' command displays the custom resources that define the Istio installation.

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MCQeasy

You are installing Istio for a development cluster and want to use a predefined configuration that includes the core components but disables unnecessary features like telemetry to save resources. Which profile should you choose?

A.preview

B.minimal

C.demo

D.default

AnswerB

The minimal profile provides the smallest footprint.

Why this answer

The 'minimal' profile installs only the base resources and the control plane, making it ideal for resource-constrained development environments.

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MCQmedium

You need to add a custom CA certificate to the Istio control plane during installation. How do you pass this using IstioOperator?

A.spec.values.global.certificates.caCertificates

B.spec.meshConfig.caCertificates

C.spec.components.pilot.k8s.env

D.spec.security.ca.path

AnswerA

This provides the required path for custom CA certificates.

Why this answer

You use the 'spec.values.global.certificates' or specific secret mounts to provide custom certificates to Istiod.

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MCQhard

You need to configure the IstioOperator CR to disable mTLS globally for a legacy migration. Which field correctly sets the global peer authentication policy?

A.spec.components.pilot.mtls: false

B.spec.meshConfig.mtls: false

C.spec.values.global.mtls.enabled: false

D.spec.security.globalMtls: false

AnswerC

This is the correct path for the Helm-based configuration in IstioOperator.

Why this answer

The 'spec.meshConfig.defaultConfig.peerAuthenticationPolicy' is not the correct path; the global mTLS setting is handled via 'spec.values.global.mtls.enabled'.

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