DNS resource records contain the information that a zone maintains about the resources (such as hosts) that the zone contains. A typical resource record consists of the:
- Name (host) of the resource record.
- Information about how long the resource record can remain in the cache.
- Resource record type, such as a host (A) resource record.
- Data that's specific lớn the record type, such as the host's IPv4 address.
You can add resource records directly, or they can be added automatically when Windows-based, Dynamic Host Configuration Protocol (DHCP) enabled clients join a network using dynamic update.
Types of resource records
Common resource records include:
| Resource record type | Description |
|---|---|
| Host (A, AAAA) records | Maps a hostname lớn an IP address. |
| Alias (CNAME) records | Forward an alias domain name name or subdomain lớn another primary or canonical name. Alias (CNAME) resource records are also termed canonical name resource records. With these records, you can use more kêu ca one DNS name lớn point lớn a single host. |
| Mail exchanger (MX) records | Specifies the name of a computer that exchanges or forwards mail. E-mail applications use the mail exchanger (MX) resource record lớn locate a mail server based on a DNS domain name name in the destination address for the e-mail recipient of a message. If multiple mail exchanger (MX) resource records exist, the DNS Client service attempts lớn tương tác mail servers in the order of preference from lowest value (highest priority) lớn highest value (lowest priority). |
| Pointer (PTR) records | Used by reverse DNS lookups lớn map an IP address lớn domain name. Pointer (PTR) resource records tư vấn the reverse lookup process, based on zones that are created and rooted in the in-addr.arpa domain name. You need lớn have the appropriate reverse lookup zone present on your DNS server lớn create a PTR record that maps an IP address lớn a specific hostname. |
| Service location (SRV) records | Specifies the host, port and protocol for a service. Service location (SRV) resource records are required when clients use DNS lớn locate location services such as Active Directory domain name controllers. |
| Name server (NS) records | Specifies the authoritative name servers for a domain name. |
| Text (TXT) record | Enables the publication of text in a DNS record. Text records let you add text information that can be returned by querying DNS. TXT records are often used lớn authenticate ownership of DNS zones. |
| Delegation name (DNAME) record | Provides an alias for a domain name, lượt thích a CNAME record, but includes all subdomains. |
| Start of authority (SOA) record | Provides authoritative information about a DNS zone. The SOA record includes primary name server, tương tác of DNZ zone administrator, refresh information, and other information. |
Working with resource records and zones
Resource records can be added lớn an existing zone using the Add-DNSServerResourceRecord PowerShell command. Some common resource record types have other PowerShell commands where you don't need to specify the resource record type. You can also add resource records using the DNS Manager console. See Managing DNS resource records for guidance on working with resource records, including creating and modifying existing resource records of all types.
Next steps
- Managing DNS resource records