Which DNS record maps a hostname to an IPv4 address?

Which DNS record maps a hostname to an IPv4 address?

• A. A record
• B. AAAA record
• C. CNAME record
• D. MX record

Answer: (A)

The main idea is that DNS translates a domain name into the address a computer uses to reach a service. The A record is the one that links a hostname to an IPv4 address. It stores the IPv4 address in the familiar dotted-quad form (like 93.184.216.34), so when a client asks for a domain, DNS can return that IPv4 address. An IPv4 address is 32 bits expressed as four decimal octets. For IPv6, the AAAA record does the same job but for 128-bit addresses. A CNAME record, instead, maps a name to another domain name (an alias), not directly to an IP address. An MX record specifies the mail server for a domain, along with priority, and isn’t used to resolve a web-facing IP address.

The main idea is that DNS translates a domain name into the address a computer uses to reach a service. The A record is the one that links a hostname to an IPv4 address. It stores the IPv4 address in the familiar dotted-quad form (like 93.184.216.34), so when a client asks for a domain, DNS can return that IPv4 address. An IPv4 address is 32 bits expressed as four decimal octets. For IPv6, the AAAA record does the same job but for 128-bit addresses. A CNAME record, instead, maps a name to another domain name (an alias), not directly to an IP address. An MX record specifies the mail server for a domain, along with priority, and isn’t used to resolve a web-facing IP address.