Ch 6: DNS Record Types

AAAA

These records are the IPv6 equivalent of A records

TXT

This record type enables you to set explanatory text associated with the domain.

CNAME

A canonical name (CNAME) record links a hostname to another hostname. You may specify the record-contents either as a "bare" machine name or as a FQDN (Fully qualified domain name). In the latter case, the target system need not be in the same domain as the one specified by the SOA record. You can create multiple records for the same CNAME, each linking to another computer as a crude form of load balancing.

MX

A mail exchanger (MX) record points to a mail server for the domain. Remote mail servers access this record to learn how to deliver mail that's addresses to your domain. The record-contents of these records includes both a priority code and a computer name. As with CNAME and NS records, MX records can point to systems in other domains. the mail server must be configured to accept mail for the domain, though.

NS

A name server (NS) record provides the hostname of a DNS server for the domain. This record is used mainly by other DNS servers that are directed to yours by other systems when your DNS server functions on the Internet at large. NS records, like CNAME records, can point outside your own domain. An NS record can refer to a server for the main domain or the subdomain if you provide the subdomain name.

A

An address

PTR

Pointer (PTR) records are opposite of A records; they link IP addresses to hostnames.

SOA

The start of authority (SOA) record. This type of record is complex. It provides various administrative details for the zone. The name is the domain name foe the record, and this name is used as the default name for the record, and this name is used as the default whenever a machine name without a training dot (.) appears in subsequent records.