We help IT Professionals succeed at work.

Replication between 2 DC's stopped working

Here is the error I get when trying to manually run the replication

Error Message
Comment
Watch Question

BRONZE EXPERT
Top Expert 2013

Commented:
Are there any firewalls between the two servers? You can use tools like portqry to track those down   http://blogs.technet.com/b/abizerh/archive/2009/06/11/troubleshooting-rpc-server-is-unavailable-error-reported-in-failing-ad-replication-scenario.aspx

Can you run repadmin /replsum  What do you see there?

Any other errors in your logs?

Thanks

Mike
Hi,

The "RPC server unavailable" error can occur for the following reasons:

DNS problems

Time synchronization problem

RPC service is not running

Network connectivity problem

DNS Resolution-
1. Each DC / DNS server points to its private IP address as primary DNS server and other internal DNS servers as secondary ones
2. Each DC has just one IP address and one network adapter is enabled.  
3. Contact your ISP and get valid DNS IPs from them and add it in to the forwarders, Do not set public DNS server in TCP/IP setting.
4. Once you are done, run "ipconfig /flushdns & ipconfig /registerdns", restart DNS and NETLOGON service each DC.

TIme resolution-
Refer this article: http://abhijitw.wordpress.com/2011/10/08/time-server-configuration-to-sync-pdc-emulator-to-an-external-time-source/

RPC service-
Ensure the RPC service is running.

Network connectivity-
Ensure that the important well-known ports required in a domain environment are open on the firewall between these DCs, use the PortqryUI tool.

Refer:http://blogs.technet.com/b/abizerh/archive/2009/06/11/troubleshooting-rpc-server-is-unavailable-error-reported-in-failing-ad-replication-scenario.aspx

Author

Commented:
From SERV2003
Port Query from SERV2003
 From Serv2003

Author

Commented:
I can  ping each server from either end by:

IP
Simple name
FQDN

I think it maybe a time issue as "2003BACK" time is always off.

Author

Commented:
Port Query took quite awhile to run as this DC is very slow. Port Query didn't find any "Return Code 1"
Time configuration is important, make sure the PDC role owner in forest root domain is authorative time server and another DC, members are syncing with it.

run "ipconfig /all" and "dcidag /q"on each DC and post the result.

Author

Commented:
Here's SERV2003

 SERV2003
dcdiag /q didn't report anything

_____________________________________

Here's 2003BACK
 2003BACK
dcdiag /q
 dcdiag on 2003BACK
BRONZE EXPERT
Top Expert 2013

Commented:
They need to be within 5 minutes of each other in terms of time.

Thanks

Mike
DNS pointing on both server in NIC is not proper.

1. Each DC / DNS server points to its private IP address as primary DNS server and other DC as secondary DNS server

Please change the DNS ponting and run "ipconfig /flushdns & ipconfig /registerdns", restart DNS and NETLOGON service each DC.

wait for few minutes and check replication.



Author

Commented:
Should the Primary DNS be the other DC's IP address?
BRONZE EXPERT
Top Expert 2013
Commented:
Should the Primary DNS be the other DC's IP address?

Yes that is the preferred method to avoid race conditions

The AD team discussed this in the following blog   http://blogs.technet.com/b/askds/archive/2010/07/17/friday-mail-sack-saturday-edition.aspx#dnsbest

I also asked about the loopback in the comments you may want to check out.

Thanks

Mike

Author

Commented:
Well I think that worked. Here's DC "SERV2003"
 Event Log SERV2003
Here's DC "2003BACK
 Event Log 2003BACK
and keeping the same Time on both DC's

Suggest you to run dcdiag /q and repadmin /replsum commands to verify that the everything is in place.

Author

Commented:
Maybe not out of the woods yet.

Here's "2003BACK"
 cmd
Here's "SERV2003"
 serv2003
Everything is clean now, do not to worry about the DCDIAG output on 2003BACK, it shows there were previous error in system event log.

Author

Commented:
Okay ...that's sort of what I thought after I looked at them alittle closer.

thanks you very much abhijitwaikar and mkline71

Explore More ContentExplore courses, solutions, and other research materials related to this topic.