CDN DNS & Domain Management 2

Question 1

What DNS record type is used to map a hostname to an IPv6 address?

Accepted Answer

AAAA

Answer

AAAA records map hostnames to 128-bit IPv6 addresses, while A records handle IPv4.

Question 2

Which DNS failover strategy routes traffic to a backup CDN origin only when health checks fail?

Accepted Answer

Active-passive failover

Answer

Active-passive failover keeps a secondary endpoint idle until the primary fails a health check.

Question 3

A CDN provider uses DNS-based load balancing to distribute users across PoPs. What latency metric does the DNS resolver typically use to select the nearest PoP?

Accepted Answer

RTT to the resolver's IP

Answer

CDN authoritative DNS servers measure round-trip time (RTT) from the resolver's IP to select the closest PoP.

Question 4

What is the purpose of DNSSEC's RRSIG record?

Accepted Answer

It contains a cryptographic signature over a DNS record set

Answer

RRSIG holds the digital signature for a resource record set, allowing resolvers to verify authenticity.

Question 5

When a CDN edge node receives a DNS query for content.example.com, which authoritative server is ultimately responsible for answering?

Accepted Answer

The authoritative nameserver listed in example.com's NS records

Answer

The authoritative nameserver designated by the domain's NS records holds the final, definitive answer for that zone.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN DNS & Domain Management 2