When a domain training.citrix.com resolution is not available in resolver cache or Local DNS, where will the request be forwarded next?

When a domain training.citrix.com resolution is not available in resolver cache or Local DNS, where will the request be forwarded next?

• A. Root server
• B. Authoritative Name server
• C. Top-level Domain server
• D. Second-level Domain server

Answer: (A)

When a resolver cannot find the domain in its cache, the next step is to ask a root DNS server. Root servers are the starting point of DNS lookups for names that aren’t cached anywhere yet. They don’t give the final IP themselves, but they refer the resolver to the appropriate Top-Level Domain (TLD) server for the domain’s suffix—in this case, the .com TLD. The resolver would then query the .com TLD server, which would refer it to the authoritative server for citrix.com, and finally retrieve the IP from that authoritative source.

When a resolver cannot find the domain in its cache, the next step is to ask a root DNS server. Root servers are the starting point of DNS lookups for names that aren’t cached anywhere yet. They don’t give the final IP themselves, but they refer the resolver to the appropriate Top-Level Domain (TLD) server for the domain’s suffix—in this case, the .com TLD. The resolver would then query the .com TLD server, which would refer it to the authoritative server for citrix.com, and finally retrieve the IP from that authoritative source.