See the following article in the Microsoft Knowledge Base for more information:
977158 DNS updates may be incorrectly reported as failed when you use a third-party DNS server application for DNS registration on a computer that is running Windows Server 2008 R2 or Windows 7
After deploying Windows Server 2008 R2 domain controllers in an environment using BIND DNS Servers, the following symptoms are observed:
- Windows Server 2008 R2 domain controllers successfully register DNS SRV records but log NETLOGON error Event 5774 with status code 9502 in the System log each time DNS SRV records are dynamically registered. Active Directory domain controllers dynamically register approximately 15 to 30 SRV records every hour and log this event for each registration attempt.
Log Name: System
Source: NETLOGON
Event ID: 5774
Level: Error
Description:
The dynamic registration of the DNS record '._tcp.dc._msdcs.. 600 IN SRV 0 100 88 xxx.yyy.zzz' failed on the following DNS server:
DNS server IP address:
Returned Response Code (RCODE): 0
Returned Status Code: 9502
For computers and users to locate this domain controller, this record must be registered in DNS.
USER ACTION
Determine what might have caused this failure, resolve the problem, and initiate registration of the DNS records by the domain controller. To determine what might have caused this failure, run DCDiag.exe. To learn more about DCDiag.exe, see Help and Support Center. To initiate registration of the DNS records by this domain controller, run 'nltest.exe /dsregdns' from the command prompt on the domain controller or restart Net Logon service. Or, you can manually add this record to DNS, but it is not recommended.
ADDITIONAL DATA
Error Value: Bad DNS packet
The error status code 9502 decimal (0x251 hex) indicates symbolic error DNS_ERROR_BAD_PACKET with friendly error "Bad DNS packet." - The %SystemRoot%\Debug\NETLOGON.LOG file on the domain controller logging the Event 5774 contains:
YY/MM HH:MM:SS [MISC] Eventlog: 5774 (1) "<record>.<DNS zone>.<AD DNS domain>. 600 IN A <DNS IP>" 9502 "<IP Address>" "0" "9502" <snip> - If you run the DCDIAG tool, the output will contain:
An error event occurred. EventID: 0x0000168E
Time Generated: <date> <time>
Event String:
The dynamic registration of the DNS record '<record>.<DNS zone>. 600 IN A <DNS Server IP>' failed on the following DNS server: - DC Locator code will assume that the DNS record registration failed and hence will not deregister the DNS records if needed (during demotion). This will cause stale DNS records to exist until DNS expires (scavenges) the records.
- Monitoring systems will raise the alert for error Event 5774 (NELOG_NetlogonDynamicDnsRegisterFailure) which can result in unnecessary administrative overhead as administrators investigate those false positive alerts.
The symptoms above are known to occur when using BIND 9.2.2.