no-start-connection Azure AD Connect

Question

I'm in a multi-domain configuration (5). After several months of correct operation, I have synchronization problems on one of the domains. Error code: 0,x31,0x35, 0x51.

If I restart my domain controllers, the first synchronization works but not the following ones.

The domain in error is under Windows server 2022.

I've checked the password for the MSOL_xxx account.

The VPN is up and works. I can ping my AD from AAD Connect VM.

Have you encountered this type of problem before?

Answer 1

Hello @Alfredo - ALFREDO REVILLA , I found the origin of the problem. The VPN is up and running but not properly.

Thank you for your answer.
I close the ticket.

Answer 2

@Fabien LE MELLEC

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this!

• Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others", I'll repost your solution in case you'd like to accept the answer.

Issue:

You weren't having any issues for several months with Azure AD Connect within your multi-domain configuration. However, you recently started noticing sync issues and after restarting your domain controller the first sync worked as expected but the following syncs were having issues.

I'm in a multi-domain configuration (5). After several months of correct operation, I have synchronization problems on one of the domains. Error code: 0,x31,0x35, 0x51.

• If I restart my domain controllers, the first synchronization works but not the following ones.
• The domain in error is under Windows server 2022.
• I've checked the password for the MSOL_xxx account.
• The VPN is up and works. I can ping my AD from AAD Connect VM.

Solution:

After troubleshooting your issue, you found that your VPN was up and running but not properly.

I found the origin of the problem. The VPN is up and running but not properly.

• If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.

I hope this helps!

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If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.