Cloud DNS for domain management in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

How does Cloud DNS handle DNS record updates?

You update a DNS record in Cloud DNS. What happens immediately after the update?

A The update is applied only after the DNS zone is manually reloaded.

B The update propagates gradually based on the TTL of the DNS record.

C The update requires restarting the Cloud DNS service to take effect.

D The update is instantly visible worldwide with zero delay.

💡 Hint

Think about how DNS caching works globally.

DNS updates in Cloud DNS propagate based on the TTL (Time To Live) value of the DNS record. This means changes are not instant worldwide but gradually visible as caches expire.

❓ Architecture

intermediate

Choosing DNS zone type for domain management

You want to manage DNS records for your public website domain using Cloud DNS. Which DNS zone type should you create?

A Forwarding DNS zone to forward queries to another DNS server.

B Private DNS zone to restrict DNS resolution to your internal network.

C Reverse DNS zone to map IP addresses back to domain names.

D Public DNS zone to allow global DNS resolution for your domain.

💡 Hint

Consider if your domain should be visible on the internet.

Public DNS zones are used to manage DNS records for domains accessible globally on the internet. Private zones are for internal networks only.

❓ security

advanced

Securing DNS updates in Cloud DNS

Which method provides the best security to prevent unauthorized DNS record changes in Cloud DNS?

A Use a VPN to connect to Cloud DNS for updates.

B Enable DNSSEC to encrypt DNS record updates.

C Use IAM roles to restrict who can update DNS zones.

D Disable all DNS updates except during business hours.

💡 Hint

Think about controlling access permissions.

IAM roles allow fine-grained control over who can update DNS zones, preventing unauthorized changes. DNSSEC protects DNS data integrity but does not control update permissions.

❓ Configuration

advanced

Configuring a DNS A record for a VM instance

You want to create a DNS A record in Cloud DNS that points app.example.com to the external IP of your VM instance. Which configuration is correct?

A Name: app.example.com., Type: A, TTL: 300, Data: 35.192.0.1

B Name: app, Type: A, TTL: 300, Data: 35.192.0.1

C Name: app.example.com, Type: CNAME, TTL: 300, Data: 35.192.0.1

D Name: app.example.com., Type: A, TTL: 300, Data: app.example.com

💡 Hint

Remember the correct record type and format for IP addresses.

An A record maps a domain name to an IPv4 address. The name must be fully qualified with a trailing dot. CNAME cannot point directly to an IP address.

✅ Best Practice

expert

Designing DNS for high availability and low latency

You want to design Cloud DNS for a global application to ensure high availability and low latency DNS resolution. Which approach is best?

A Use a single public DNS zone and rely on Cloud DNS global anycast infrastructure.

B Create private DNS zones in each region and forward queries to them.

C Manually update DNS records with different IPs based on user location.

D Create multiple public DNS zones with the same domain name in different regions.

💡 Hint

Think about how Cloud DNS handles global traffic.

Cloud DNS uses a global anycast network to serve DNS queries from the nearest location automatically, providing high availability and low latency with a single public DNS zone.