RE: [ActiveDir] Replication Problem After DC Demotion

[Abouelnasr, Jerry]

Title: Replication Problem After DC Demotion

That’s good to know Brian.   The information that we came across and thought might be relevant is posted below for anyone who may find it of value.     http://technet2.microsoft.com/WindowsServer/en/Library/c238f32b-4400-4a0c-b4fb-7b0febecfc731033.mspx?mfr=true     Excluded Nonresponding Servers The KCC automatically rebuilds the replication topology when it recognizes that a domain controller has failed or is unresponsive. The criteria that the KCC uses to determine when a domain controller is not responsive depend upon whether the server computer is within the site or not. Two thresholds must be reached before a domain controller is declared “unavailable” by the KCC: • The requesting domain controller must have made n attempts to replicate from the target domain controller. • For replication between sites, the default value of n is 1 attempt. • For replication within a site, the following distinctions are made between the two immediate neighbors (in the ring) and the optimizing connections: For immediate neighbors, the default value of n is 0 failed attempts. Thus, as soon as an attempt fails, a new server is tried. For optimizing connections, the default value of n is 1 failed attempt. Thus, as soon as a second failed attempt occurs, a new server is tried. • A certain amount of time must have passed since the last successful replication attempt. • For replication between sites, the default time is 2 hours. • For replication within a site, a distinction is made between the two immediate neighbors (in the ring) and the optimizing connections: For immediate neighbors, the default time is 2 hours. For optimizing connections, the default value is 12 hours. You can edit the registry to modify the thresholds for excluding nonresponding servers.   Ushruf Abouelnasr IT Analyst II | City of Pasadena | ITSD (V) 626-744-3951 | (F) 626-396-7951 Email: [EMAIL PROTECTED]   From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Desmond Sent: Thursday, July 13, 2006 7:00 PM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Replication Problem After DC Demotion   You can run repadmin /kcc to force the KCC…   Thanks, Brian Desmond [EMAIL PROTECTED]   c - 312.731.3132   From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Riley, Devin Sent: Thursday, July 13, 2006 8:19 PM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Replication Problem After DC Demotion   A coworker has researched the issue and found that the KCC could take two hours to fix the replication link. We have about a half hour to go to see if this is the case. So I think your idea of letting it bake a little while longer may do the trick   I will post more information if the problem continues. Devin Riley Sr. Systems Engineer City of Pasadena, Department of Finance Information Technology Services Division Phone: 626-744-7072 Fax: 626-396-7300     From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Linehan Sent: Thursday, July 13, 2006 5:56 PM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Replication Problem After DC Demotion From that machine can you run and post the output of repadmin /showreps /v ?  Is the affected server Windows 2000 or Windows Server 2003 and what SP levels?  I assume you also did not set any preferred bridgehead settings?  You could also use ADLB.exe in report only mode to see the topology.  I am guessing that if you let it bake a little more it will correct itself.  Also what is the replication interval set on that site link, the minimum 15 minutes?   Thanks,   -Steve   From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Riley, Devin Sent: Thursday, July 13, 2006 7:35 PM To: ActiveDir@mail.activedir.org Subject: [ActiveDir] Replication Problem After DC Demotion   We just demoted a W2K DC in our primary site. The demotion was successful and the NTDS object associated with the DC was removed from AD Sites & Services. In our only other site, the one domain controller is reporting replication problems. Replmon is reporting the following: The DSA Operation is unable to proceed because of a DNS lookup failure. The error code from replmon is 8524 Over an hour has passed. The replication topology is automatic and we have all default settings in regards to replication schedules etc. Any suggestions? Devin