Windows 2000 Host Cannot Join the Domain (266324)

SYMPTOMS

When you attempt to add a host to a Windows 2000 domain, the attempt may be unsuccessful and the following error message may be displayed:

Network Identification
The following error occurred validating the name Domainname
The specified domain either does not exist or could not be contacted.

CAUSE

This behavior can occur if the Domain Name System (DNS) zone file that is parallel to the Active Directory domain uses an alias (CNAME) record as the target host of the Service Locator (SRV) records rather than a host or A record. For example:

   _ldap._tcp.dc._msdcs    600 SRV    0 100 389 pdc.<Domain>
   pdc                     600 CNAME  dc1.<Domain>
   dc1                     600 A      192.168.0.1

NOTE: The target host in this example is pdc.Domain which is an alias to the host dc1.

NOTE: This may also occur if packet filtering/firewall software is blocking ports needed to connect, such as TCP port 389.

RESOLUTION

To resolve this problem, change the target host of every SRV record in the DNS zone for Active Directory to point to a host or A record.

MORE INFORMATION

SRV records are used in an Active Directory domain to locate domain controllers that are running Lightweight Directory Access Protocol (LDAP) and Kerberos services. RFC 2782 states that the target host for an SRV record must not be an alias. When you join a domain in Windows 2000, the client queries for the SRV record of _ldap._tcp.dc._msdcs.Domain. If the SRV record points to an alias rather than a host record, the client suspends its attempt to join the domain and returns an error message.