DNS is a hierarchically distributed database that creates hierarchical names that can be resolved to IP addresses. The IP addresses are then resolved to MAC addresses. DNS is the primary name registration and resolution service in Windows Server 2003. DNS provides a hierarchically distributed and scalable database; provides name registration, name resolution and service location for Windows 2000 and Windows Server 2003 clients; and locates domain controllers. The namespace used by DNS is a hierarchical namespace, or hierarchical system.
The DNS components and concepts are summarized below. While the remainder of this Article focuses on planning and implementing a DNS namespace, the DNS components and concepts listed below are used throughout the discussion.
•Fully qualified domain name (FQDN): This is the DNS name that is used to identify a computer on the network. FQDNs have to be unique. The FQDN usually consists of a Host name, Primary DNS suffix, and Period.
•DNS Name: A DNS name is a name that can include a number of labels that are segregated by a dot. When a DNS name displays the entire path, it is known as the Fully Qualified Domain Name (FQDN).
•Alias: This is name used instead of another name. The Canonical Name (CNAME) is an alias name in DNS.
•Primary DNS suffix: Computers running in a Windows Server 2003 network are assigned primary DNS suffixes for name registration and name resolution purposes. The primary DNS suffix is also referred to as the primary domain name, or domain name.
•Connection-specific DNS suffix: This is a DNS suffix which is assigned to an adapter. The connection-specific DNS suffix is called the adapter DNS suffix.
•DNS server: This is a computer running the DNS Server service that provides domain name services. The DNS server manages the DNS database it hosts. The information in the database of a DNS server pertains to a portion of the DNS domain tree structure or namespace. This information is used to provide responses to client requests for name resolution. The following types of DNS servers exist:
oPrimary DNS server: This DNS server owns the zones defined in its DNS database, and can make changes to these zones. A standard primary DNS server is a name server that obtains zone data from the local DNS database, thereby making the primary DNS server authoritative for the zone data that it contains.
oSecondary DNS server: This DNS server obtains a read-only copy of zones via DNS zone transfers. A secondary DNS server cannot make any changes to the information contained in its read-only copy. DNS Notify is a mechanism that enables a primary DNS server to inform secondary DNS servers when its database has been updated. The mechanism informs secondary DNS servers when they need to initiate a zone transfer so that the updates of the primary DNS server can be replicated to them.
oCaching-only DNS servers: These servers do not host zones, and are not authoritative for any DNS domain. The information stored by caching-only DNS servers is the name resolution data that it has ...