In a GSLB deployment for www.citrix.com using two Citrix ADCs, which DNS record must be added on the parent DNS server to delegate requests to the ADCs?

In a GSLB deployment for www.citrix.com using two Citrix ADCs, which DNS record must be added on the parent DNS server to delegate requests to the ADCs?

• A. Canonical Name (CNAME)
• B. Address (A) record
• C. Name Server (NS) record
• D. Pointer Record (PTR)

Answer: (C)

Delegating authority for a subdomain to the ADCs is done with DNS NS records on the parent zone. In a GSLB setup for www.citrix.com using two Citrix ADCs, you want the parent DNS to hand off queries for the relevant subdomain to the ADCs that are authoritative for that zone. By creating NS records on the parent server that point to the ADCs’ name servers, you designate them as the authoritative sources for that subdomain, allowing the ADCs to respond with the appropriate GSLB decisions (traffic routing, health status, etc.). An A record would simply map a host to an IP address and does not delegate authority; a CNAME would alias one name to another rather than delegate the zone, and a PTR is for reverse lookups, not delegation.

Delegating authority for a subdomain to the ADCs is done with DNS NS records on the parent zone. In a GSLB setup for www.citrix.com using two Citrix ADCs, you want the parent DNS to hand off queries for the relevant subdomain to the ADCs that are authoritative for that zone. By creating NS records on the parent server that point to the ADCs’ name servers, you designate them as the authoritative sources for that subdomain, allowing the ADCs to respond with the appropriate GSLB decisions (traffic routing, health status, etc.).

An A record would simply map a host to an IP address and does not delegate authority; a CNAME would alias one name to another rather than delegate the zone, and a PTR is for reverse lookups, not delegation.