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PCNE · domain

Configuring Network Services

Practise identifying, configuring, and troubleshooting core network services like DNS, DHCP, NAT, and NTP for the PCNE exam.

219 questions49 easy104 medium66 hard

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What this domain covers

What to know about Configuring Network Services

Tests your knowledge of DNS, DHCP, NAT, and other network services configuration and troubleshooting.

DNS record types and resolution process

DHCP lease, scope, and reservation configuration

NAT and PAT for IP address translation

Network time protocol (NTP) synchronization

Why learners struggle

Why Configuring Network Services questions are commonly missed

Network services questions are commonly missed because candidates confuse protocol roles and port numbers. The overlap between DNS, DHCP, and NAT functions creates specific mix-ups.

  • ·DNS vs DHCP — name resolution vs IP assignment
  • ·NAT vs PAT — address vs port translation
  • ·DHCP scope vs reservation — dynamic vs static
  • ·DNS A vs AAAA — IPv4 vs IPv6 records
  • ·NTP vs SNTP — accuracy vs simplicity
  • ·DHCP relay vs DHCP server — forwarding vs providing

Watch out for

Common Configuring Network Services exam traps

  • Confusing DNS A record with CNAME for hostname mapping
  • Thinking DHCP assigns static IPs instead of dynamic leases
  • Mixing up NAT and PAT port vs address translation
  • Assuming NTP only syncs time once, not periodically

Question index

All Configuring Network Services questions (219)

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1

A company has an on-premises data center connected to GCP via Cloud Interconnect. They want to expose an on-premises service to internet clients through Google Cloud's global load balancer. Which type of network endpoint group should they use?

Medium
2

Drag and drop the steps to set up a Google Cloud Armor security policy for a backend service into the correct order.

Medium
3

A company wants to expose a set of internal services running on Compute Engine instances in a private VPC to other internal services using HTTP load balancing. They require L7 features like URL-based routing and SSL termination. Which load balancer should they use?

Medium
4

An organization uses Traffic Director with Envoy sidecars in GKE. They want to implement fault injection to test service resilience by injecting a 5-second delay into 10% of requests to a specific backend service. Which Traffic Director configuration resource should they use?

Hard
5

A company is designing a global web application that must serve users worldwide with low latency. They plan to use a Global HTTPS Load Balancer with Cloud CDN. Which TWO features should they enable to further reduce latency for users connecting from various regions? (Choose two.)

Medium
6

A company uses Cloud DNS. They want to override DNS resolution for a specific domain (e.g., mycompany.com) to point to an internal IP for all queries originating from their VPC, while leaving all other domains unaffected. Which Cloud DNS feature should they use?

Hard
7

Drag and drop the steps to set up a Cloud Interconnect connection for dedicated on-premises connectivity into the correct order.

Medium
8

A company wants to use Traffic Director to implement fault injection for testing service resilience. They want to inject delays and errors into a percentage of requests. Which two configurations are required? (Choose two.)

Medium
9

You are configuring an SSL Proxy load balancer for HTTPS traffic. The backend service points to an instance group with a self-managed certificate. The load balancer's frontend uses a Google-managed certificate. Clients receive SSL errors indicating certificate mismatch. What is the most likely cause?

Medium
10

A company uses Cloud NAT for outbound internet access. Engineering notices that some VM instances fail to connect to external services during peak hours. The network engineer suspects port exhaustion. Which action would best mitigate this issue?

Medium
11

You need to configure a health check for a gRPC-based backend service. Which protocol should you use for the health check?

Medium
12

An engineer wants to use Cloud DNS to override DNS responses for a specific domain within their VPC. Which feature should they use?

Hard
13

A company has deployed an HTTP load balancer with a backend service configured to use an unmanaged instance group. Users report that traffic is not reaching the backend instances. The backend instances are healthy and have proper firewall rules allowing traffic from the load balancer. What step should the network engineer take to resolve the issue?

Easy
14

A company is using Cloud NAT to allow private instances to access the internet. They notice that some instances are not able to reach certain external services. Which THREE steps should they take to troubleshoot?

Hard
15

Your organization has an internal HTTP load balancer (ILB) in us-central1. The backend service is a managed instance group with a health check on port 8080. Recently, some instances are reported as unhealthy despite the application running fine. What is the most likely cause?

Medium
16

A company wants to protect their application behind an external HTTP(S) load balancer from SQL injection attacks. Which Cloud Armor feature should be used?

Medium
17

A company is using Traffic Director with Envoy sidecar proxies to manage traffic between microservices. They want to gradually shift 5% of traffic from version v1 to v2 of a service for testing. Which Traffic Director resource should they configure?

Hard
18

A company is deploying a global web application on Google Cloud. They need to serve traffic from the closest region to users, support both HTTP and HTTPS, and offload SSL/TLS termination at the load balancer. Which load balancing solution should they use?

Medium
19

Refer to the exhibit. A DNS managed zone is configured with private visibility and associated with a VPC network. A Compute Engine instance in a different VPC network tries to resolve 'test.example.com' but fails. What is the most likely reason?

Medium
20

A security team wants to serve private content through Cloud CDN but restrict access to only authorized users. They need to generate time-limited URLs that do not require users to log in. Which approach should they use?

Hard
21

You need to configure Cloud CDN to cache all content from a backend bucket, ignoring any Cache-Control headers sent by the origin. Which cache mode should you use?

Easy
22

Your company has a hybrid cloud architecture with two on-premises data centers: DC1 and DC2. Each DC is connected to Google Cloud via separate Cloud VPN tunnels (tunnel1 from DC1, tunnel2 from DC2) to a VPC in us-west1. The VPC has two subnets: subnet-a (10.0.1.0/24) and subnet-b (10.0.2.0/24). DC1 has a subnet 192.168.1.0/24 and DC2 has 192.168.2.0/24. You configure BGP on both tunnels with the VPC dynamic routing, and each on-premises router advertises its local subnet. The VPC automatically imports the learned routes. You notice that traffic from DC1 to an instance in subnet-a (10.0.1.5) works, but traffic from DC2 to the same instance fails intermittently. Additionally, traffic from DC2 to DC1 (192.168.1.0/24) fails completely. You check the route tables and see that both tunnels have learned the routes for the remote subnets. What is the most likely cause and solution?

Hard
23

A developer wants to use Cloud CDN to cache content from a backend bucket. They want to cache all objects regardless of cache-control headers, but need to exclude certain URL patterns (e.g., /private/*) from caching. Which cache mode should they choose?

Medium
24

A service provider uses a Shared VPC with multiple service projects. The host project has a Cloud NAT configured for subnet 10.1.0.0/24 to provide outbound internet access to all service projects using that subnet. A new service project needs to use its own Cloud NAT for its VM instances in subnet 10.1.0.0/24 to meet compliance requirements. The network engineer attempts to create a Cloud NAT in the service project for that subnet but receives an error that the subnet already has a NAT gateway. What action should the engineer take to meet the compliance requirement?

Easy
25

You are designing a multi-tier application where an internal HTTP(S) load balancer should route requests to a backend service based on the URL path (e.g., /api/* to one service, /web/* to another). Which component is essential for this routing?

Medium
26

A company uses Private Service Connect (PSC) to access a managed SaaS application published by another company. The SaaS provider publishes a service attachment in their VPC. Which resource must the consumer create to connect to the service?

Easy
27

A company runs a private GKE cluster in us-central1. Pods need to access the internet for updates. Which configuration is required?

Easy
28

A company uses Cloud NAT to enable outbound internet access for private instances in a VPC. They notice that some instances are unable to connect to external services, while others can. The network team has verified that all instances have the same tags and are in the same subnet. Which TWO actions should the team take to troubleshoot the issue?

Hard
29

Which Traffic Director feature ensures that a service does not receive more requests than it can handle by setting a maximum number of concurrent requests or connections?

Easy
30

A network engineer notices unusual traffic patterns from a VM. They want to capture detailed information about each packet sent and received by the VM, including source and destination IPs, protocols, and ports. Which feature should they enable?

Easy
31

An organization has deployed an internal TCP/UDP load balancer in their VPC. They need to ensure that the load balancer preserves the client IP address when forwarding traffic to backend instances. Which configuration is required?

Hard
32

A company uses Cloud DNS with a managed zone for example.com. They want to override DNS responses for a specific subdomain, mail.example.com, to point to an internal IP address when queried from within the VPC, but external queries should resolve normally. Which feature should they use?

Hard
33

A company wants to securely connect an on-premises data center to a VPC in us-central1. The on-premises network uses RFC 1918 addresses (10.0.0.0/8) that overlap with the VPC subnet (10.0.1.0/24). They need connectivity to specific workloads in the VPC without changing IP addresses on premises. What should they do?

Medium
34

A company has a TCP-based application running on a group of Compute Engine VMs in us-central1. They need to provide a static internal IP address to clients within the VPC, while preserving the client source IP for logging. Which load balancer should they use?

Medium
35

A media company uses Cloud CDN with signed URLs to distribute premium video content. They need to revoke access for a specific user immediately. Which approach should they take?

Hard
36

A company is migrating on-premises DNS to Google Cloud. They have a hybrid network using Cloud VPN and want to resolve on-premises hostnames from Compute Engine instances without custom scripts. Which service should they use?

Hard
37

You are configuring a Regional Internal HTTP(S) Load Balancer for a service that must only be accessible from within a VPC. The backend is a zonal NEG of Compute Engine instances. The load balancer is not receiving traffic. What is a likely cause?

Hard
38

Which THREE factors should be considered when choosing between a global external HTTP(S) load balancer and a regional external HTTP(S) load balancer? (Choose 3.)

Medium
39

An organization is deploying a Shared VPC with one host project and three service projects. Each service project has multiple VPC networks. They want to ensure that only the host project's network admin can create firewall rules affecting the shared VPC network. Which architecture satisfies this requirement?

Hard
40

A company runs a microservices application on Google Kubernetes Engine (GKE) with an Envoy sidecar proxy for each service. They want to use Traffic Director to apply traffic policies such as traffic splitting between versions and fault injection. Which API does Traffic Director use to configure Envoy proxies?

Medium
41

An engineer is deploying a Regional External HTTP(S) Load Balancer to serve a web application on Compute Engine. They want to maintain the highest availability by automatically rerouting traffic away from unhealthy instances. Which additional configuration is required?

Medium
42

An engineer is configuring a Global HTTPS Load Balancer with a backend service that points to a serverless NEG for Cloud Functions. The health checks are failing. What is the most likely cause?

Medium
43

A company wants to expose a web application running on Cloud Run globally with a single anycast IP address, using HTTP(S) load balancing and Cloud CDN for static content. The application should be accessible at https://app.example.com. What is the correct configuration?

Medium
44

You need to configure SSL certificates for a Global HTTPS Load Balancer. The certificate should be automatically provisioned and managed by Google. Which type of certificate should you use?

Easy
45

You need to migrate traffic gradually from an old version of a microservice to a new version using Traffic Director. You want to send 10% of traffic to the new version and 90% to the old version. Which configuration should you use?

Medium
46

A gaming company uses Cloud Armor with an external HTTP(S) load balancer to protect against DDoS attacks. They need to restrict access to the load balancer based on geographic region. What should they configure?

Medium
47

An organization has a Dedicated Interconnect with Cloud Router configured for BGP. The on-premises network advertises a prefix that overlaps with an existing VPC subnet. How does Google Cloud handle the overlapping prefix?

Hard
48

What is the purpose of a Response Policy Zone (RPZ) in Cloud DNS?

Easy
49

Which load balancer type preserves the client source IP address and can be used for TCP/UDP traffic on a specific port, passing traffic through to backend instances without proxy overhead?

Easy
50

A company wants to serve private content from Cloud CDN using signed URLs that expire after 1 hour. Which steps are required to enable this?

Medium
51

A large enterprise is migrating to Google Cloud and needs to establish connectivity between on-premises and VPCs in two different regions (us-east1 and europe-west1). They have a single Partner Interconnect connection at a co-location facility in New York. They want to use the same interconnect for both regions. Which configuration should they use?

Hard
52

A company uses Cloud DNS with a managed zone for 'example.com'. They want to implement a failover routing policy so that if the primary health check fails, traffic is sent to a secondary IP. Which THREE resources need to be configured? (Choose three.)

Medium
53

You need to create a serverless Network Endpoint Group (NEG) to attach to a Global HTTPS Load Balancer backend for a Cloud Run service. Which command should you use?

Easy
54

An organization wants to serve private content via Cloud CDN, ensuring that only authorized users can access cached objects. They need to generate time-limited access for specific URLs. Which method should they use?

Medium
55

A company wants to connect two VPCs in the same project using VPC Network Peering. Each VPC has non-overlapping subnets. What is the minimum number of peering connections required to enable full bidirectional communication?

Easy
56

A company wants to expose a web application running on Cloud Run globally with the lowest latency and automatic SSL termination. Which load balancer should they use?

Easy
57

An engineer configures a Global HTTPS Load Balancer with a backend service pointing to an instance group. The health check is set to HTTP on port 80, check interval 5s, timeout 5s, healthy threshold 1, unhealthy threshold 1. After deployment, instances are marked unhealthy despite the application responding correctly on port 80. What is the most likely cause?

Hard
58

A company wants to set up a Regional Internal HTTP(S) Load Balancer to serve an internal web application. Which two components are required? (Choose two.)

Medium
59

You are configuring a Global External HTTPS Load Balancer. Which TWO components are required to route traffic to a Cloud Run service via a serverless NEG? (Select two.)

Medium
60

A company wants to serve global static content from a Cloud Storage bucket. They need low latency worldwide and SSL termination at the edge. Which solution should they choose?

Medium
61

A company uses a Global HTTPS Load Balancer with Cloud CDN. They need to purge specific cached objects for all users immediately after a content update. Which method should they use?

Hard
62

An organization wants to distribute incoming HTTPS traffic across a set of Compute Engine instances in multiple regions, with SSL termination at the Google Cloud edge. They also need to protect against DDoS attacks at the edge. Which load balancing solution should they choose?

Easy
63

Your company runs a multi-tier web application on Google Cloud. The frontend is in us-central1 (3 instances behind an external HTTP(S) Load Balancer), the backend is in us-west1 (3 instances behind an internal TCP/UDP Load Balancer). The frontend instances are in a managed instance group (MIG) with autoscaling based on CPU utilization. Recently, you noticed that during traffic spikes, the frontend instances' CPU utilization remains low, but the backend instances' CPU utilization spikes to 90% and causes timeouts. The application uses a synchronous REST API; the frontend instances make requests to the internal load balancer's IP. What should you do to resolve the backend scaling issue?

Hard
64

You need to route traffic to different backend services based on the URL path: /api/* goes to a Cloud Run service, /static/* goes to a Cloud Storage bucket, and /* goes to a Compute Engine instance group. Which component of the Global HTTPS Load Balancer should you configure?

Medium
65

A company is using a Global SSL Proxy Load Balancer to terminate SSL and forward traffic to a backend service on Compute Engine. They need to preserve the client IP address in the backend logs. What should they do?

Hard
66

A large organization uses Shared VPC with multiple service projects. They have an on-premises network connected via Cloud Interconnect. They want the on-premises network to be able to reach instances in all service projects. What is the recommended configuration?

Hard
67

An organization needs to serve a TCP-based application globally with low latency but without SSL termination. Which load balancer should they use?

Medium
68

A company is migrating on-premises services to Google Cloud. They have a hybrid connectivity NEG that points to an on-premises endpoint via a Cloud VPN tunnel. The Traffic Director service mesh is configured to route traffic to that NEG. However, traffic to the on-premises service is failing with connection timeouts. What is the most likely cause?

Hard
69

Which TWO network services are required to enable private Google access for on-premises hosts using a Dedicated Interconnect connection? (Choose two.)

Medium
70

A company runs a microservices application on Google Kubernetes Engine (GKE) and wants to expose an HTTP service to the internet using a global HTTPS load balancer. They need to enable Cloud CDN for static content and use a custom domain with a Google-managed SSL certificate. Which three resources must be created? (Choose three.)

Medium
71

An organization runs a stateful TCP application on a group of Compute Engine instances in us-central1. Clients must connect to the service using a single anycast IP address, and the load balancer must preserve the client source IP address. Which load balancing option meets these requirements?

Medium
72

Which TWO of the following are required when setting up an internal TCP/UDP load balancer (ILB) in a shared VPC environment?

Medium
73

A company wants to use Cloud CDN to accelerate content delivery globally. Which TWO of the following are valid cache key components that can be configured in Cloud CDN? (Choose 2)

Medium
74

A company hosts a web application on Cloud Run and wants to serve content from a Cloud Storage bucket for static assets. They plan to use a global HTTPS load balancer with a URL map to route requests. Which backend type should they configure for the static content?

Medium
75

A company wants to expose a web application running on Cloud Run to the internet with a single global IP address, SSL termination, and Cloud CDN. Which load balancer should they use?

Easy
76

A company uses Traffic Director with Envoy proxies to manage east-west traffic. They want to implement fault injection to test the resilience of their service mesh. Which TWO types of faults can they inject? (Choose two.)

Hard
77

An organization configures a Global external HTTP(S) Load Balancer with Cloud CDN. They notice that some users are getting stale content even after they have invalidated the cache for specific objects. What is the most likely reason?

Hard
78

A security team wants to allow traffic from a specific set of VMs with service account 'web-sa@project.iam.gserviceaccount.com' to access a database VM with tag 'db'. The VMs are in the same VPC. Which firewall rule configuration achieves this?

Medium
79

You are using Cloud CDN with a backend bucket and want to cache all responses regardless of Cache-Control headers. Which cache mode should you set?

Hard
80

You need to create a load balancer that distributes traffic across Compute Engine instances in multiple regions for a TCP application without SSL offload. The clients should connect to a single anycast IP. Which load balancer should you use?

Medium
81

A financial services company needs to audit all VPC firewall rule changes in real time. They want to receive notifications whenever a rule is created, modified, or deleted. What is the most efficient way to achieve this?

Medium
82

A company needs to load balance TCP traffic without SSL termination for a gaming application where client IP preservation is critical. The backend is a group of Compute Engine instances. Which load balancer types meet these requirements? (Choose TWO.)

Medium
83

A company wants to expose a globally distributed application using Cloud Run via a single anycast IP address, with SSL termination and content-based routing to different backend services. Which load balancer should they use?

Medium
84

A company has deployed an external HTTPS load balancer with a Cloud CDN backend. The load balancer uses a managed SSL certificate. Recently, the company updated their DNS record to point to a different IP address of a new load balancer. After the change, some users are still being served from the old load balancer's cache. The network engineer has confirmed that the DNS TTL has expired. What is the most likely cause of this issue?

Hard
85

A company has an on-premises data center connected to GCP via Cloud VPN with dynamic routing (BGP). Recently, connectivity to a specific subnet (10.1.0.0/16) in GCP became intermittent. The VPN tunnel is up, and BGP sessions are established. What is the most likely cause?

Medium
86

A company wants to use Cloud DNS to distribute traffic across multiple regional endpoints with failover: primary in us-central1, secondary in us-west1. If the primary health check fails, traffic should go to secondary. Which routing policy should they use?

Medium
87

A company wants to enable mTLS between microservices in a service mesh managed by Traffic Director. They have deployed Envoy sidecars. What must be configured to enforce mTLS?

Medium
88

A company uses Traffic Director with Envoy sidecars. They want to implement traffic splitting to gradually migrate traffic from version v1 to v2 of a service. Which TWO resources must be configured? (Select two.)

Hard
89

A team is using Traffic Director with Envoy sidecars. They want to enforce mutual TLS (mTLS) between services. Which configuration must be enabled?

Easy
90

A company has a VPC with multiple subnets and uses Cloud VPN tunnels to connect to on-premises. They want to ensure that only traffic destined for on-premises is sent through the VPN tunnels; all other traffic should use the internet. Which route configuration should they implement?

Hard
91

You are designing a global web application that uses Cloud Run for the backend and Cloud Storage for static assets. You need to serve content securely over HTTPS with a custom domain, using Cloud CDN for caching. Which resources must be created or configured? (Choose three.)

Hard
92

A company has deployed a Global External Application Load Balancer with Premium Tier and enables Cloud CDN. Users in Europe report high latency, while users in the US have good performance. The backend is a regional NEG in us-west1. What is the most likely cause?

Medium
93

An engineer creates a Cloud NAT configuration as shown in the exhibit. The test-instance is created without an external IP address. However, the instance cannot reach the internet. What is the most likely cause?

Easy
94

A multinational company has a Shared VPC environment with multiple service projects. They need to allow a specific service project to use its own Cloud DNS private zone that resolves to internal IPs in the Shared VPC. Which configuration ensures this without exposing the zone to other projects?

Hard
95

Match each network pricing model to its description.

Medium
96

A network engineer configures a Global external HTTP(S) Load Balancer with a serverless NEG backend pointing to Cloud Run. The load balancer returns 502 Bad Gateway errors. What is the most likely cause?

Hard
97

Your company uses Cloud DNS with a managed zone for example.com. You need to override DNS responses for a specific domain (e.g., internal.example.com) to point to an internal IP address. Which Cloud DNS feature should you use?

Medium
98

Which TWO of the following load balancer types can distribute traffic to backends in multiple regions?

Easy
99

A company uses Cloud NAT to allow private VMs to access the internet. They notice that some VMs are unable to reach a specific set of external IP addresses, but other VMs can. The firewall rules are correctly configured. What is the most likely cause?

Hard
100

A company wants to use Cloud CDN to cache content from a backend bucket. They need to cache all objects, including those with cookies, to maximize performance. Which cache mode should they select?

Medium
101

A company wants to expose a web application running on Compute Engine behind a global HTTPS load balancer with Cloud CDN enabled. They need to ensure that only authenticated users can access certain content. Which approach should they use?

Easy
102

A company has Compute Engine instances in a VPC that only have internal IP addresses. They need to access Google Cloud services like Cloud Storage and BigQuery. They also have on-premises servers that need to access the same instances via a Cloud VPN tunnel. What must be enabled for the instances to access Google APIs without public IPs?

Hard
103

You want to distribute traffic across multiple GKE clusters in different regions with automatic failover if a region becomes unhealthy. Which Cloud DNS routing policy should you use?

Medium
104

You have a Cloud Router with the configuration shown. The on-premises network (ASN 65002) is not receiving any routes from Google Cloud. What is the most likely cause?

Hard
105

A company uses Traffic Director with Envoy sidecars for service mesh. They want to gradually shift traffic from version 1 to version 2 of a service, starting with 10% traffic to version 2. Which Traffic Director feature should they use?

Medium
106

A company wants to use Cloud CDN to serve content from a custom origin that is not hosted on Google Cloud. They have enabled Cloud CDN with a backend bucket pointing to an external origin URL. However, content is not being cached. What is a likely reason?

Hard
107

An engineer manages a global application using Global external HTTP(S) Load Balancer with URL map routing to multiple backend services. They want to enable Cloud CDN for the /images/* path. What is the correct way to enable CDN for that specific path?

Medium
108

You are using Traffic Director with Envoy sidecars for a microservices application. You want to inject artificial delays into requests from service A to service B for testing purposes. Which Traffic Director feature should you use?

Hard
109

A company is migrating an on-premises DNS service to Cloud DNS. They want to resolve on-premises hostnames from GCP VMs and resolve Google Cloud private zone names from on-premises. They have a Cloud VPN with BGP. Which architecture should they implement?

Medium
110

A company is running workloads on Compute Engine instances without public IP addresses. They need to allow these instances to securely access the internet for software updates. Which Google Cloud service should be configured?

Easy
111

A company has a Dedicated Interconnect connection from their on-premises data center to GCP. They have set up BGP sessions over VLAN attachments to peer with their VPC. Traffic from on-premises to GCP works, but return traffic from GCP to on-premises is dropped at the on-premises firewall. What is the most likely cause?

Hard
112

A company is deploying a global application on Google Cloud using Cloud Load Balancing. They want to serve traffic from multiple regions and require the lowest possible latency for users worldwide. The application serves HTTP traffic and uses a static IP address. Which load balancing solution should they use?

Medium
113

Which TWO of the following are benefits of using Cloud NAT?

Medium
114

Which THREE actions should you take to secure a VPC that hosts public-facing web applications?

Hard
115

A team is using Traffic Director with Envoy sidecars. They want to enforce mutual TLS (mTLS) between all services. Which component is responsible for issuing and distributing certificates to the Envoy proxies?

Hard
116

A company runs a global e-commerce platform with a monolithic application deployed on Compute Engine. They want to modernize by splitting the monolith into microservices running on Cloud Run and Cloud Functions, and expose them externally via a single anycast IP with Google-managed SSL certificates. Which load balancer should they use?

Medium
117

A company wants to expose an on-premises HTTP server to internet clients through a Global HTTPS Load Balancer using a hybrid connectivity NEG. The on-prem server is reachable via a Cloud VPN tunnel. What must the engineer configure to ensure the load balancer can reach the on-prem endpoint?

Hard
118

An organization wants to direct traffic from a global load balancer to an on-premises data center using a hybrid connectivity NEG. Which connectivity option must be in place for this to work?

Easy
119

You are configuring a health check for a backend service that expects gRPC health probing. Which protocol should the health check use to verify gRPC service health?

Medium
120

A network engineer is configuring a global HTTPS load balancer with Cloud CDN. They want to cache responses based on the request origin, query parameters, and user agent. Which cache key configuration should they use?

Hard
121

A company has a global e-commerce platform using a Global HTTPS Load Balancer with Cloud CDN. They want to serve private content, such as user-specific PDFs, with CDN caching while ensuring only authorized users can access it. Which method should they use?

Medium
122

A media streaming company uses Cloud CDN with signed URLs to protect content. They want to invalidate cached content for a specific file after a security incident. The file is stored in a Cloud Storage bucket and the CDN cache key includes the URL. They run: gcloud compute url-maps invalidate-cdn-cache URL_MAP --path "/videos/incident.mp4". The invalidation succeeds but the old content is still served. What is the most likely reason?

Hard
123

A network engineer is troubleshooting a global HTTPS load balancer that is not serving traffic to some users. The load balancer has a backend service with a zonal NEG in us-central1-a. Users report intermittent 502 errors. Which two checks should the engineer perform? (Choose two.)

Hard
124

A company uses Cloud CDN to serve content. They need to generate signed URLs to allow temporary access to premium content. They have set up a signing key. Which command correctly generates a signed URL for the object /video.mp4 in a bucket served by a load balancer?

Hard
125

You are migrating an on-premises application to Google Cloud and need to connect it to Cloud Run services via a load balancer. The on-premises network uses a VPN to GCP. Which TWO components are required to route traffic from on-premises to a serverless NEG? (Choose 2)

Hard
126

A company uses Cloud Armor with an external HTTPS load balancer to protect their web application. They have a security policy 'my-policy' attached to the backend service. The policy includes an allow rule (priority 1000) for their corporate IP range (203.0.113.0/24) and a deny rule (priority 2000) for all other IPs. The company has an office at a remote location that uses a different IP range (198.51.100.0/24). Employees from the remote office report they cannot access the application. Meanwhile, employees from the corporate office (203.0.113.0/24) can access. The engineer checks the Cloud Armor policy and sees the rule configuration as shown. What is the most likely cause?

Hard
127

Refer to the exhibit. A VM in 'subnet-a' can access Google APIs via private IP, but a VM in 'subnet-b' cannot. What change should be made to fix this?

Easy
128

You are deploying a microservices architecture on Google Kubernetes Engine (GKE) with Traffic Director for traffic management. You want to implement fault injection to test the resilience of your services. Which two types of fault injection does Traffic Director support? (Choose two.)

Medium
129

You need to configure health checks for a backend service that uses gRPC for health checking. Which health check type should you use?

Easy
130

A company wants to use Cloud DNS to route traffic to multiple IP addresses for a domain, with the ability to direct users based on their geographic location and also failover to a backup region if the primary is unhealthy. Which DNS routing policies should be combined? (Choose two.)

Medium
131

Refer to the exhibit. A Compute Engine instance has the network tags 'http-server' and 'ssh-server'. It also has a public IP address. Which of the following statements about traffic to this instance is true?

Easy
132

Refer to the exhibit. A network team has created this load balancer. Clients inside the VPC are unable to connect to the load balancer's IP address from a Compute Engine instance in the same VPC. What is the most likely cause?

Hard
133

A company uses an internal TCP/UDP load balancer to distribute traffic to a backend service. The backend instances are in an unmanaged instance group. Some instances fail health checks and are removed. What happens to existing connections to failed instances?

Medium
134

You need to allow on-premises servers to access a Google Cloud VM's internal IP without using a public IP. The on-premises network is connected via Cloud VPN. What configuration is required on the Google Cloud side?

Easy
135

Refer to the exhibit. The Cloud Router is configured with custom BGP advertisements. The on-premises router receives only the two advertised ranges (10.1.0.0/24 and 10.2.0.0/24) but not the VPC subnets (e.g., 10.3.0.0/24). What is the most likely reason?

Hard
136

A company wants to expose an internal HTTP service running on Compute Engine instances to other VPCs in the same project using a load balancer. The load balancer must support HTTP path-based routing and preserve the client source IP. Which load balancer types meet these requirements? (Choose two.)

Medium
137

A company wants to expose a global web application with HTTP/HTTPS load balancing, SSL termination, and Cloud CDN. They need to route requests to different backend services based on the URL path (e.g., /api/* to a Cloud Run service, /static/* to a Cloud Storage bucket, and /* to a managed instance group). Which GCP load balancing product should they use?

Easy
138

A company is migrating from an on-premises data center to Google Cloud. They have a legacy TCP application that must preserve client IP addresses when load balanced. They also need SSL termination for a different web application. Which TWO load balancers should they consider? (Choose two.)

Medium
139

Which TWO steps are required to set up a Cloud VPN with dynamic routing (BGP)? (Choose 2.)

Easy
140

A company wants to use Cloud DNS with a failover routing policy. They have two IP addresses serving the same application: primary in us-east1 and secondary in us-west1. They want traffic to go to primary unless health check fails, then fail over to secondary. Which configuration is required?

Medium
141

A developer needs to store a TLS certificate for use with a load balancer. Which Google Cloud service is used to create and manage SSL certificates?

Easy
142

A company wants to use Cloud CDN to serve private content to authenticated users only. Which feature should they use?

Medium
143

An organization uses Cloud DNS private zones for internal service discovery. They want to override DNS responses for a specific domain (e.g., 'internal.example.com') to block access to malicious domains and redirect certain queries to a different IP for compliance. Which Cloud DNS feature should they use?

Hard
144

A company wants to cache static content globally to reduce latency for their users. They are using a Global HTTPS Load Balancer with a backend bucket. Which Cloud CDN cache mode should they use?

Medium
145

A developer wants to use Cloud CDN to cache content from an external origin backend. Which TWO configurations are required to set this up? (Choose two.)

Easy
146

An engineer wants to use Traffic Director to split traffic between two versions of a microservice running on Compute Engine with Envoy sidecars. They want to send 10% of traffic to the new version. Which configuration should they apply?

Medium
147

An organization is migrating a legacy application to GCP. The application requires a static internal IP address for a Compute Engine VM that must persist even if the VM is stopped or deleted. Which IP address type should they assign?

Easy
148

A company wants to use Cloud DNS response policy zones (RPZ) to override DNS responses for a set of internal domains. They need to ensure that only specific VPC networks can use these overrides. Which three steps are required? (Choose three.)

Hard
149

Your company uses Network Connectivity Center (NCC) to manage multiple on-premises sites connected via Cloud VPN and Partner Interconnect. You create a NCC hub and attach spokes (VPN tunnels and VLAN attachments). Traffic between two on-premises sites (Site A and Site B) should flow through Google Cloud. However, traffic is not passing between the sites. What is the most likely cause?

Hard
150

While configuring a health check for a backend service, an engineer notices that the health check is failing even though the instances are healthy. The health check is HTTP on port 80 with a request path of /health. The instances respond to curl http://localhost:80/health with 200 OK. What is a likely cause?

Hard
151

An organization needs to set up a Regional Internal HTTPS Load Balancer for internal microservices. They want to use Envoy-based load balancing. Which backend type must the backend service use?

Medium
152

An engineer is configuring a Global SSL Proxy Load Balancer to terminate SSL for a non-HTTP TCP application. They want to minimize latency by allowing the load balancer to reuse connections to backends. Which setting should they adjust?

Medium
153

A company is using Cloud DNS for private zone resolution within their VPC. They have a private zone for 'example.internal' and have attached it to the VPC. When they create a new Compute Engine VM and try to resolve 'myapp.example.internal', it fails. What is the most likely cause?

Easy
154

A company wants to distribute traffic across multiple backend services based on the geographic location of the user. They are using an external HTTPS load balancer. Which routing configuration should they use?

Medium
155

A company needs to map multiple domain names to different backend services on a single Global HTTPS Load Balancer. Which resource should they configure to direct traffic based on the requested hostname?

Easy
156

A global e-commerce company has deployed a web application across multiple GCP regions using an external HTTPS load balancer. Traffic is expected to originate from users worldwide. They want to minimize latency and improve user experience, while also ensuring that traffic is served from the nearest healthy backend. Which load balancing configuration should they use?

Hard
157

An organization uses Cloud DNS with a managed zone for example.com. They want to block or override DNS queries for a specific malicious domain (malware.com) to return a sinkhole IP address. Which Cloud DNS feature should they use?

Medium
158

A team needs to perform a health check for a gRPC backend service. Which health check type should they use?

Easy
159

Your security team wants to block specific SQL injection attacks using Cloud Armor. You have configured a security policy with a preconfigured WAF rule for SQL injection (evaluatePreconfiguredExpr('sqli-stable')). The rule is set to DENY. However, legitimate traffic is being blocked intermittently. What should you adjust?

Medium
160

A company wants to load balance TCP traffic (non-HTTP) across a group of Compute Engine instances in a single region, while preserving the client IP address. They also need to support session affinity based on client IP. Which load balancer should they choose?

Medium
161

A company wants to route traffic to different backend services based on the geographic location of the client. Which Cloud DNS routing policy should they use?

Medium
162

A company has a VPC with subnet 10.1.0.0/24 in us-central1. They created a Cloud NAT gateway named 'nat-us-central1' attached to that subnet. During peak hours, many VM instances in the subnet cannot connect to the internet. The NAT configuration shows only one NAT IP. Firewall rules allow egress traffic, and health checks confirm the NAT gateway is functioning. What is the most likely cause of the failure?

Easy
163

Refer to the exhibit. A Cloud Router has two BGP sessions. The first session is UP, the second is DOWN. What is the most likely cause for the second session being down?

Hard
164

You need to configure a health check for a backend service that uses HTTP2. Which THREE settings must be configured correctly for the health check to work? (Select three.)

Medium
165

A company is designing a hybrid network using Dedicated Interconnect. They want to configure BGP for load balancing across multiple VLAN attachments. Which TWO statements are correct?

Medium
166

Your company has deployed a hybrid cloud environment with a Cloud VPN tunnel between Google Cloud VPC and an on-premises data center. The VPC has a custom mode with subnet 10.0.1.0/24 in us-east1. On-premises uses subnet 192.168.1.0/24. The VPN tunnel is established using dynamic routing (BGP). Both sides advertise the correct prefixes. A Compute Engine VM in the VPC (10.0.1.10) can ping the on-premises gateway (192.168.1.1), but cannot ping a server on-premises (192.168.1.100). The on-premises network team confirms that 192.168.1.100 is reachable from the on-premises gateway. Firewall rules in GCP allow ingress from 192.168.1.0/24 to all VMs. What is the most likely cause?

Medium
167

Refer to the exhibit. A VM with the 'ssh-allowed' tag is unreachable via SSH from the internet, while other VMs with the same tag work. What is the most likely cause?

Medium
168

A company is using Traffic Director with Envoy sidecars to manage traffic between microservices. They want to inject faults to test service resilience. Which Traffic Director feature should they use?

Hard
169

A company's application requires TLS termination at the load balancer, with backend instances in multiple regions running on Compute Engine. The backend instances must see the original client IP address. Which load balancer should be used?

Hard
170

Which TWO configurations can enable VM instances without external IPs to access the internet? (Choose TWO.)

Easy
171

Which TWO are best practices for securing a VPC network? (Choose 2.)

Medium
172

Which THREE of the following are requirements for VPC Network Peering?

Hard
173

You need to invalidate Cloud CDN cached content for specific URLs after updating files in Cloud Storage. Which command should you use?

Medium
174

A global HTTPS load balancer is configured with a backend service that points to a serverless NEG for Cloud Run services. Some requests are failing with 502 errors. What is a likely cause?

Medium
175

A cloud engineer is configuring a Global External HTTPS Load Balancer with a backend service that targets a Cloud Run service via a serverless NEG. They want to enable Cloud CDN and set cache behavior to cache all responses regardless of origin headers. Which THREE steps are required? (Choose three.)

Medium
176

An e-commerce website uses Cloud CDN to cache static content. The origin is an external HTTP load balancer. What is the benefit of enabling Cloud CDN in this scenario?

Easy
177

A company has a Global SSL Proxy Load Balancer handling HTTPS traffic. They want to offload SSL decryption to the load balancer and forward encrypted traffic to backends. Which backend protocol should they use?

Medium
178

A company has deployed a web application on Compute Engine instances in a VPC with subnet 10.1.0.0/20. The instances need to access an external API that whitelists IP addresses. The company uses Cloud NAT to provide outbound connectivity. The API integration tests are failing, and the operations team suspects that the source IP addresses seen by the API are not consistent. What is the most likely cause and solution?

Medium
179

A company uses Cloud CDN with an external HTTP(S) load balancer. They have two origin server groups: a primary in us-central1 and a backup in europe-west1. They want traffic directed to the primary unless it is unhealthy, in which case traffic should fail over to the backup. Which configuration is required?

Hard
180

Which Cloud DNS routing policy should you use to direct users to the nearest healthy backend based on their geographic location?

Easy
181

You need to distribute incoming TCP traffic to a set of Compute Engine instances in the same region while preserving the client IP address. The load balancer must be used for non-HTTP(S) workloads. Which load balancer should you choose?

Easy
182

A company is using Traffic Director with Envoy sidecars. They want to enable mutual TLS (mTLS) between services. Which two steps are required? (Choose two.)

Hard
183

Match each Cloud Load Balancing type to its description.

Medium
184

A company wants to serve static content from a Cloud Storage bucket and dynamic content from Compute Engine VMs behind a single external URL. Which GCP feature allows this configuration?

Easy
185

Which TWO considerations are important when designing a VPC peering strategy between multiple projects in Google Cloud?

Medium
186

An organization uses Cloud CDN to serve static content from a backend bucket. They want to ensure that content is always served from the edge regardless of cache-control headers from the origin. Which cache mode should they set?

Medium
187

A company has a VPC with subnets in us-central1 and europe-west1. They create a Private Service Connect endpoint for a managed service in us-central1. Can Compute Engine instances in europe-west1 access the endpoint?

Hard
188

A company uses Cloud CDN to cache content from a backend bucket. They want to ensure that only objects with a Cache-Control header indicating public cacheability are cached. Which cache mode should they select?

Medium
189

A company wants to forward DNS queries from their on-premises network to Google Cloud for resolution of private zone names. Which configuration is required?

Easy
190

An organization needs to route traffic to a group of Compute Engine VM instances in the same zone for a high-throughput TCP application. The solution must preserve the client source IP address and support connection draining. Which load balancer type meets these requirements?

Medium
191

A company is deploying an internal HTTP application on Compute Engine instances. The application must be load-balanced across multiple instances in different regions, but only accessible from within the same VPC. Which load balancer type meets these requirements?

Medium
192

An organization is deploying a Global HTTPS Load Balancer with Cloud Armor and Cloud CDN. They want to ensure that only requests with a valid signed cookie can access private content. Which three steps are required? (Choose THREE.)

Hard
193

A company has a Cloud VPN tunnel to on-premises. They want on-premises clients to resolve private DNS names in the VPC. Which service should they configure?

Easy
194

An organization uses Cloud DNS with a managed zone for internal resolution. They want to implement a failover routing policy so that if the primary health-checked endpoint is unhealthy, traffic is directed to a secondary endpoint. Which THREE steps are required? (Choose three.)

Hard
195

Which THREE components are required when configuring an internal TCP/UDP load balancer? (Choose THREE.)

Medium
196

You are deploying a new internal HTTP(S) load balancer for a microservice that runs on Compute Engine instances within the same region. The load balancer must be accessible only from within the VPC network. Which components are required? (Choose two.)

Medium
197

Which TWO network services can be used to provide secure connectivity between a VPC and an on-premises data center without traversing the public internet? (Choose two.)

Easy
198

A network engineer is configuring a Cloud Router for BGP peering with an on-premises router over a VPN tunnel. The on-premises router uses 169.254.x.x link-local addresses. Which BGP peer IP should the engineer use in the Cloud Router configuration?

Easy
199

A company wants to serve private content over Cloud CDN with access control. They need to generate time-limited URLs that allow users to download files from Cloud Storage. Which TWO methods can they use? (Choose two.)

Hard
200

To enable DNSSEC for a Cloud DNS managed zone, what must be configured?

Medium
201

A DevOps team is configuring a VPC with a subnet in us-east1. They need to allow a specific VM (source IP 10.0.1.2) to access a database VM (destination IP 10.0.2.3) on port 3306, but only from that specific source. All other traffic should be denied. Which firewall rule configuration should they use?

Medium
202

A multinational corporation has deployed a multi-region application on Google Kubernetes Engine (GKE) clusters in us-central1 and europe-west1. The application serves global users and requires low-latency access to a shared database hosted on Cloud SQL in us-central1. The network team has configured Cloud VPN tunnels between each region and the on-premises data center for administrative access. The application instances in europe-west1 are experiencing high latency when connecting to the Cloud SQL instance in us-central1. The team wants to reduce latency without migrating the database. The team has already verified that the Cloud SQL instance has private IP enabled and is peered to a shared VPC that spans both regions. The GKE clusters are in the same shared VPC. What should the team do?

Medium
203

A company has a VPC with multiple subnets. They want to restrict traffic between two specific subnets (10.0.1.0/24 and 10.0.2.0/24) while allowing all other traffic. They create a firewall rule with priority 1000 denying ingress from 10.0.1.0/24 to 10.0.2.0/24. However, traffic is still allowed. What is the most likely reason?

Hard
204

An engineer is configuring a Global HTTPS Load Balancer with a serverless NEG pointing to Cloud Run. The deployment fails with a health check error. What is the most likely cause?

Medium
205

A company has two VPC networks (VPC-A and VPC-B) in the same project. They are connected via VPC peering. VPC-A contains an internal TCP load balancer with IP 10.1.2.3 serving on port 80. VPC-B needs to access this load balancer. The network engineer has verified that the firewall rules allow traffic from VPC-B to the load balancer's IP and port. However, instances in VPC-B cannot connect to 10.1.2.3:80. What is the most likely reason for this failure?

Medium
206

A company uses Cloud VPN with dynamic routing (BGP). The on-premises network advertises a prefix that overlaps with a subnet in the VPC. Which TWO actions can resolve this conflict? (Choose TWO.)

Hard
207

A company needs to cache API responses that are dynamic but cacheable for short periods. They want to use Cloud CDN with a Global HTTPS Load Balancer. Which three settings should they configure?

Medium
208

A network engineer is designing a hybrid cloud architecture connecting an on-premises data center to Google Cloud via Dedicated Interconnect. The on-premises network uses BGP for dynamic routing. The engineer needs to configure Cloud Router to exchange routes with the on-premises router. Which two configuration steps are required? (Choose two.)

Easy
209

A developer wants to use Cloud CDN to cache static assets from an external origin (not a GCP bucket). Which backend type supports this?

Easy
210

A company has two VPC networks in the same project: Network A (hosting a private zone for 'example.internal.') and Network B. They are connected via VPC peering. The network engineer created a DNS peering zone in Network B for 'example.internal.' pointing to Network A. However, instances in Network B cannot resolve 'host.example.internal.' which is defined in Network A's private zone. The engineer verified that the peering zone is active and the networks are properly peered. What is the most likely reason for the resolution failure?

Medium
211

An organization needs to distribute incoming traffic across multiple GCE instances in the same region while preserving the client IP address. Which load balancer should they use?

Easy
212

A company uses Traffic Director with Envoy sidecars to manage traffic in their service mesh. They want to perform canary deployments where 10% of traffic goes to the new version and 90% to the stable version. Which TWO Traffic Director resources should they configure? (Choose two.)

Medium
213

A company uses Cloud NAT to allow private instances to reach the internet. They notice that egress traffic from Compute Engine VMs is intermittently failing. The VMs are in us-central1-a and use the default VPC network. Cloud NAT is configured with a single NAT IP address. What is the most likely cause?

Medium
214

A startup is deploying a microservices application on Google Kubernetes Engine (GKE). They want to expose a service to the internet using a load balancer that provides SSL termination and supports WebSocket. Which type of Service should they use?

Easy
215

Which Google Cloud service provides a managed Envoy proxy control plane for traffic management, including traffic splitting and fault injection, in a service mesh?

Easy
216

You need to create a DNS routing policy that routes users in Europe to one IP and users in Asia to a different IP, with a fallback to a default IP if no match. Which THREE elements are required? (Choose 3)

Medium
217

An application running on Google Kubernetes Engine (GKE) uses Traffic Director for traffic management with Envoy sidecars. You want to implement fault injection to test resilience by injecting a 50% failure rate on a subset of traffic. Which Traffic Director configuration should you use?

Hard
218

A company has a VPC with subnets in us-east1 and europe-west1. They have deployed a global external HTTP(S) load balancer with backend services in both regions. Users in Europe report high latency. What is the most likely cause?

Medium
219

A company uses Cloud NAT to enable outbound connectivity for private VMs. They notice that some VMs are not able to reach a specific external IP range. The VMs have no tags or service accounts. What is the most likely cause?

Easy

Frequently asked questions

What does the Configuring Network Services domain cover on the PCNE exam?
Tests your knowledge of DNS, DHCP, NAT, and other network services configuration and troubleshooting.
How many questions are in this domain?
This page lists all 219 Configuring Network Services questions in the PCNE question bank. The actual exam draws from this domain proportionally to its weighting in the official exam blueprint.
What is the best way to practise this domain?
Start with a short focused session (10 questions) to identify gaps, then work through explanations. Repeat with a longer session once the weak areas feel solid.
Can I practise only Configuring Network Services questions?
Yes — the session launcher on this page filters questions to this domain only. Choose any session length for inline explanations and scoring.