Managing DNS records
After you create the necessary zone files, you can add records to the zones. Computers that need to be accessed from Active Directory and DNS domains must have DNS records. Although there are many types of DNS records, most of these record types aren’t commonly used. So rather than focus on record types you probably won’t use, let’s focus on the ones you will use:
? A (IPv4 address) Maps a host name to an IPv4 address. When a computer has multiple adapter cards, IPv4 addresses, or both, it should have multiple address records.
? AAAA (IPv6 address) Maps a host name to an IPv6 address. When a computer has multiple adapter cards, IPv6 addresses, or both, it should have multiple address records.
? CNAME (canonical name) Sets an alias for a host name. For example, by using this record, zeta.microsoft.com can have an alias of www.microsoft.com.
? MX (mail exchanger) Specifies a mail exchange server for the domain, which enables email messages to be delivered to the correct mail servers in the domain.
? NS (name server) Specifies a name server for the domain, which enables DNS lookups within various zones. Each primary and secondary name server should be declared through this record.
? PTR (pointer) Creates a pointer that maps an IP address to a host name for reverse lookups.
? SOA (start of authority) Declares the host that’s the most authoritative for the zone and, as such, is the best source of DNS information for the zone. Each zone file must have an SOA record (which is created automatically when you add a zone). Also declares other information about the zone, such as the responsible person, refresh interval, retry interval, and so on.
? SRV (service location) Locates a server providing a specific service. Active Directory uses SRV records to locate domain controllers, global catalog servers, LDAP servers, and Kerberos servers. Most SRV records are created automatically. For example, Active Directory creates an SRV record when you promote a domain controller. LDAP servers can add an SRV record to indicate they are available to handle LDAP requests in a particular zone.