SRV Records of Domain Controller in DNS Zone

   The following knowledge helps you to determine the problem if SRV records of a domain controller is not registered in the DNS Zone of that domain.

   The following may happen when SRV records of a domain controller are not registered in DNS Zone of that domain:

• All the client computers make take long time to log on to the domain.
• Client computers stuck at Applying Computer Settings.
• Group Policy settings may not apply.
• Folder Redirection policy is not working
• Software Installation is not working.
• Replication between domain controllers is not happening.
• An application is giving error about SRV records. An application may use DNS to locate domain controllers by sending SRV queries.
• Nslookup returns error when querying using SRV records.
• Pinging of SRV records (_ldap, _keberos etc) are not successful.
• Group Policy Objects are not syncing.

   The SRV records may be the cause the above. The SRV Records of a domain controller in the domain plays an important role in Active Directory. Active Directory can not work without a DNS server. The DNS server in Active Directory is used to locate Domain Controllers in the forest or domain with the help of SRV records. Service Records or SRV records are registered specifically for domain controllers when you promote a member server to domain controller. The Netlogon service on domain controller is responsible to register SRV records.

   You can use the following methods to re-register SRV records of a domain controller in the domain DNS zone:

1. Restart the Netlogon service on domain controller.
2. Run DcDiag /fix
3. Run NetDiag /ifx
4. Re-register from Netlogon.dns file in \Windows or Winnt\System32\Config directory.

   The Netlogon.dns file is created when you promote a member server to domain controller.

http://msmvps.com/blogs/systmprog/archive/tags/Active+Directory/default.aspx