Which type of record should you request?

Your network consists of an Active Directory domain named contoso.com. You have a computer named computer1.contoso.com. Your network is configured to use only IPv6. You need to request that a DNS record be created to enable users to connect to your computer by using the name dev.contoso.com.

Which type of record should you request?
A . A
B . AAAA
C . HINFO
D . NAPTR

View Answer

Answer: B

Explanation:

The resolution of host names to IPv6 addresses is accomplished through DNS (apart from link-local addresses that are not stored by DNS and resolve automatically). The procedure is the same as for IPv4 address resolution with the computer name and IPv6 address pair being stored in a AAAA (quad-A) DNS resource record, which is equivalent to an A or host record for IPv4. Reverse DNS lookup that returns a computer name for an IPv6 address is implemented by a pointer (PTR) DNS resource record that is referred to the IPv6 reverse lookup zone (or tree) ipv6.arpa, which is the equivalent of the in-addr.arpa reverse lookup zone in Ipv4.

AAAA

An AAAA (quad-A) resource record resolves a host name to an IPv6 address.

A

An A (address) resource record resolves a host name to an IPv4 address.

HINFO

Host information (HINFO) resource record. Specifies the type of CPU and operating system in the cpu_type and os_type fields, respectively, for the host DNS domain name in the owner field. Well-known CPU and operating system types that are most often used are noted in RFC 1700. This information can be used by application protocols such as FTP, which use special procedures when communicating with computers of a known CPU and operating system type.

NAPTR

The NAPTR represents a Naming Authority Pointer. NAPTR records map between sets of URNs, URLs and plain domain names and suggest to clients what protocol should be used to talk to the mapped resource. Each NAPTR record contains a service name, a set of flags, a regexp rule, an order value, a preference and a replacement. Multiple records can be chained together in a cascade to rewrite URIs in fairly sophisticated, but deterministic ways. These cascading rules have been standardized in RFC2915 and RFC3403.