Configuring multiple names

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Configuring multiple names

Computers running Windows XP and servers running Windows Server 2003 are given DNS names by default. Each computer can have its DNS names configured using one of two possible methods:

• A primary DNS domain name, which applies as the default fully qualified DNS name for the computer and all of its configured network connections.

• A connection-specific DNS domain name, which can be configured as an alternate DNS domain name that applies only for a single network adapter installed and configured on the computer.

Although most computers do not need to support or use more than one name in DNS, support for configuring multiple connection-specific DNS names is sometimes useful. For example, by using multiple names, a user could specify which network connection to use when connecting to a multihomed computer.

Example: Using connection-specific names

As shown in the following figure, a multihomed server computer named "host-a" can be named according to both its primary and connection-specific DNS domain names.

In this example, the server computer host-a attaches to two separate subnets -- Subnet 1 and Subnet 2 -- which are also linked at redundant points using two routers for additional paths between each subnet. Given this configuration, host-a provides access as follows through its separately named local area network (LAN) connections:

• The name "host-a.public.example.microsoft.com" provides access using LAN connection 1 over Subnet 1, a lower-speed (10 megabit) Ethernet LAN, for normal access to users who have typical file and print service needs.

• The name "host-a.backup.example.microsoft.com" provides access using LAN connection 2 over Subnet 2, a higher-speed (100 megabit) Ethernet LAN, for reserved access by server applications and administrators who have special needs, such as troubleshooting server networking problems, performing network-based backup, or replicating zone data between servers.

In addition to the connection-specific DNS names, the computer can also be accessible using either of the two LAN connections by specifying its primary DNS domain name, "host-a.example.microsoft.com".

When configured as shown, a computer can register resource records in DNS according to its three distinct names and sets of IP addresses, as shown in the following table:

DNS name	IP addresses	Description
host-a.example.microsoft.com	10.1.1.11, 10.2.2.22	Primary DNS name for computer. The computer registers A and PTR resource records for all configured IP addresses under this name in the "example.microsoft.com" zone.
host-a.public.example.microsoft.com	10.1.1.11	Connection-specific DNS name for LAN connection 1, which registers A and PTR resource records for IP address 10.1.1.11 in the "public.example.microsoft.com" zone.
host-a.backup.example.microsoft.com	10.2.2.22	Connection-specific DNS name for LAN connection 2, which registers A and PTR resource records for IP address 10.2.2.22 in the "backup.example.microsoft.com" zone.

Important

• By default, the primary DNS suffix portion of a computer's fully qualified domain name (FQDN) must be the same as the name of the Active Directory domain where the computer is located. To allow different primary DNS suffixes, a domain administrator may create a restricted list of allowed suffixes by creating the msDS-AllowedDNSSuffixes attribute in the domain object container. This attribute is created and managed by the domain administrator using Active Directory Service Interfaces or the Lightweight Directory Access Protocol (LDAP).

  For more information, see Programming interfaces and Directory access protocol.

Notes

• DNS names can be set using remote administration and other remote configuration services, such as DHCP. For a DNS server running Windows Server 2003, the primary DNS domain name can be set using either remote administration or the unattended setup option.

• For connection-specific naming, you can use TCP/IP configuration methods. You can manually configure the DNS domain name for each connection that appears in the Network Connections folder or use a DHCP option type (option code 15). For more information, see Advanced configuration.

• For more information about DHCP options, see "DHCP Options" at the Microsoft Windows Resource Kits Web site.