This problem typically occurs when an attempt to establish a replication link fails as a result of a Domain Name System (DNS) lookup problem. If you receive Event ID 1925 with the error message that DNS lookup failed, inbound replication of a directory partition has failed on the destination domain controller, and you must fix the DNS problem.
The following is an example of the event text:
Log Name: Directory ServiceSource: Microsoft-Windows-ActiveDirectory_DomainServiceDate: 3/12/2008 8:14:13 AMEvent ID: 1925Task Category: Knowledge Consistency Checker Level: WarningKeywords: ClassicUser: ANONYMOUS LOGONComputer: DC3.contoso.comDescription:The attempt to establish a replication link for the following writable directory partition failed. Directory partition: CN=Configuration,DC=contoso,DC=com Source directory service: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=contoso,DC=com Source domain controller address: f8786828-ecf5-4b7d-ad12-8ab60178f7cd._msdcs.contoso.com Intersite transport (if any): CN=IP,CN=Inter-Site Transports,CN=Sites,CN=Configuration,DC=constoso,DC=comThis domain controller will be unable to replicate with the source domain controller until this problem is corrected. User Action Verify if the source domain controller is accessible or network connectivity is available. Additional Data Error value: 8524 The DSA operation is unable to proceed because of a DNS lookup failure.