Which DNS record is used to resolve a fully-qualified domain name (FQDN) to an IPv6 address?

Which DNS record is used to resolve a fully-qualified domain name (FQDN) to an IPv6 address?

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

Answer: (B)

The AAAA record is specifically designed to resolve a fully-qualified domain name (FQDN) to an IPv6 address. This is essential for networks utilizing the IPv6 protocol, allowing users and systems to access resources using human-readable domain names instead of numerical IP addresses. When a client requests the IP address associated with a domain name that uses IPv6, the DNS system looks for the AAAA record corresponding to that FQDN. If it finds a corresponding AAAA record, it returns the associated IPv6 address to the client, enabling successful connectivity to the desired resource. The other record types have different purposes: the A record resolves FQDNs to IPv4 addresses, the CNAME record is used for aliases to other domain names, and the PTR record is utilized for reverse DNS lookups, mapping IP addresses back to domain names. Each of these plays a unique role in the DNS infrastructure, but the AAAA record is distinctly focused on IPv6 address resolution.

The AAAA record is specifically designed to resolve a fully-qualified domain name (FQDN) to an IPv6 address. This is essential for networks utilizing the IPv6 protocol, allowing users and systems to access resources using human-readable domain names instead of numerical IP addresses.

When a client requests the IP address associated with a domain name that uses IPv6, the DNS system looks for the AAAA record corresponding to that FQDN. If it finds a corresponding AAAA record, it returns the associated IPv6 address to the client, enabling successful connectivity to the desired resource.

The other record types have different purposes: the A record resolves FQDNs to IPv4 addresses, the CNAME record is used for aliases to other domain names, and the PTR record is utilized for reverse DNS lookups, mapping IP addresses back to domain names. Each of these plays a unique role in the DNS infrastructure, but the AAAA record is distinctly focused on IPv6 address resolution.