CDN DNS & Domain Management 5

Question 1

Which DNS record type is used to define the hostname and port of a CDN's streaming media service endpoint?

Accepted Answer

SRV

Answer

SRV records specify both the hostname and TCP/UDP port for a specific service, enabling clients to discover service endpoints automatically.

Question 2

What happens to DNS resolution if all of a CDN domain's authoritative nameservers become unreachable simultaneously?

Accepted Answer

DNS resolution fails; clients cannot reach the CDN until at least one nameserver recovers

Answer

Without any reachable authoritative nameserver, recursive resolvers cannot obtain DNS answers and resolution fails entirely.

Question 3

A CDN operator wants to ensure that DNS queries from European users are answered by European PoPs. Which feature should be configured on the authoritative DNS?

Accepted Answer

GeoDNS (geography-based DNS routing)

Answer

GeoDNS inspects the requester's IP geolocation and returns records pointing to the nearest regional PoP.

Question 4

What is the role of glue records in DNS, and when are they required for a CDN's nameservers?

Accepted Answer

They provide A records for nameservers within the same zone to break circular delegation dependencies

Answer

Glue records are A records in the parent zone for in-bailiwick nameservers, preventing a chicken-and-egg resolution loop.

Question 5

Which protocol encrypts DNS queries between a client and resolver to prevent eavesdropping and manipulation?

Accepted Answer

DNS over HTTPS (DoH) or DNS over TLS (DoT)

Answer

DoH (port 443) and DoT (port 853) wrap DNS queries in TLS, providing confidentiality that DNSSEC alone cannot offer.

(CDN) Content Delivery Network Certification Practice Test

(CDN) Content Delivery Network Certification Practice Test

CDN DNS & Domain Management 5