DNS
Records
Record Type
|
Use
|
SOA (Start of Authority)
|
The first record in any DNS
database file is the SOA. It defines the general parameters for the DNS zone,
and it is assigned to the DNS server hosting the primary copy of a zone.
There is only one SOA record, and it is the first record in the zone database
file. The SOA record includes parameters such as the authoritative server and
the zone file serial number.
|
NS (name server)
|
The NS resource record identifies
all name servers that can perform name resolution for the zone. Typically,
there is an entry for the primary server and all secondary servers for the
zone (all authoritative DNS servers).
|
A (host address)
|
The A record maps an IPv4 (32-bit)
DNS host name to an IP address. This is the most common resource record type.
|
AAAA (quad-A)
|
The AAAA record maps an IPv6
(128-bit) DNS host name to an IP address.
|
MX (Mail Exchanger)
|
The MX record identifies servers
that can be used to deliver e-mail.
|
CNAME (canonical name)
|
The CNAME record provides
alternate names (or aliases) to hosts that already have a host record. Using
a single A record with multiple CNAME records means that when the IP address
changes, only the one A record needs to be modified.
Common uses of a CNAME record
include:
|
DNAME (Domain Alias)
|
The DNAME record provides
alternate names (or aliases) to domains that already have a host record.
|
SRV (service locator)
|
The SRV record is used by Windows
Server 2008 to register network services. This allows clients to find
services (such as domain controllers) through DNS. Windows 2008 automatically
creates these records as needed and during domain controller installation.
|
PTR (pointer)
|
In a reverse lookup zone, the PTR
record maps an IP address to a host name (i.e. "points" to an A
record). Where IPv4 PTR records are created in the in-addr.arpa namespace,
reverse lookup zones for IPv6 addresses should be created in the ip6.arpa
namespace.
(Note: When you manually
create an A record, you can choose to create the corresponding PTR record at
the same time. Creating the PTR record will fail if the reverse lookup zone
does not exist.)
|
WINS and WINS-R resource records
|
Add these records to a zone when
you want to allow DNS to use WINS resolution. The WINS resource record allows
DNS queries that fail to resolve to be forwarded to the WINS servers in the
WINS resource record. The WINS-R resource record allows the resolution of a
reverse query that is not resolvable through DNS.
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