Which DNS record is described in the material as mapping an IP address to a hostname and is used most often for DNS lookups?

Which DNS record is described in the material as mapping an IP address to a hostname and is used most often for DNS lookups?

• A. PTR
• B. CNAME
• C. NS
• D. A

Answer: (D)

In DNS, the typical path people rely on is forward resolution, where a domain name is translated into an IP address. The A record is what ties a hostname to an IPv4 address, and this is the workhorse behind most DNS lookups. When you type a domain into a browser, the resolver asks for the A record to get the address to connect to, making it the most common and essential type for day-to-day DNS operations. PTR records are used for reverse lookups—mapping an IP back to a hostname—often used in diagnostics or mail/server checks, not for the usual client web requests. NS records specify which servers are authoritative for a domain, not the address a client uses to reach the site. CNAMEs provide aliases from one name to another but ultimately still require an A (or AAAA) record to obtain the actual address. Therefore, the A record is the best choice for the reason it directly provides the address used in the common DNS lookup path.

In DNS, the typical path people rely on is forward resolution, where a domain name is translated into an IP address. The A record is what ties a hostname to an IPv4 address, and this is the workhorse behind most DNS lookups. When you type a domain into a browser, the resolver asks for the A record to get the address to connect to, making it the most common and essential type for day-to-day DNS operations.

PTR records are used for reverse lookups—mapping an IP back to a hostname—often used in diagnostics or mail/server checks, not for the usual client web requests. NS records specify which servers are authoritative for a domain, not the address a client uses to reach the site. CNAMEs provide aliases from one name to another but ultimately still require an A (or AAAA) record to obtain the actual address. Therefore, the A record is the best choice for the reason it directly provides the address used in the common DNS lookup path.