AD replication error 1722: “The RPC server is unavailable” can be resolved with help from our experts.

At Bobcares, we offer solutions for every query, big and small, as a part of our VPN Provider Support.

Let’s take a look at how our Support Team is ready to help customers with AD replication error 1722: The RPC server is unavailable.

How to resolve AD replication error 1722: The RPC server is unavailable

According to our Support Team the AD replication error 1722 results in one or more of the following symptoms:

• The DCPROMO Promotion of a replica DC does not succeed in creating an NTDS Settings object on DC with error 1722.

  The operation failed because: Active Directory Domain Services could not create the 
  NTDS Settings object for this Active Directory Domain Controller CN=NTDS Settings,
  CN=,CN=Sites,CN=Configuration,DC= on the remote AD DC ... Ensure the provided network 
  credentials have sufficient permissions. "The RPC server is unavailable."
• Furthermore, DCDIAG reports Active Directory Replications test failure with error 1722.

  [Replications Check,] A recent replication attempt failed: From to Naming Context: 
  The replication generated an error (1722): The RPC server is unavailable. 
  The failure occurred at . The last success occurred at . failures have occurred 
  since the last success. [] DsBindWithSpnEx() failed with error 1722, The RPC 
  server is unavailable.. Printing RPC Extended Error Info: 
• REPADMIN.EXE reports the failure of replication attempt with status 1722 (0x6ba)
• Moreover, the Active Directory Sites and Services’ Replicate command returns The RPC server is unavailable.

  
• Additionally, we will notice NTDS General, NTDS Knowledge Consistency Checker (KCC), or Microsoft-Windows-ActiveDirectory_DomainService events with 1722 error status in the service event log.

What is the cause behind AD replication error 1722

RPC is a layer between the application protocol and the network transport. Interestingly, Error 1722 occurs when a lower layer protocol runs into a connectivity failure. Additionally, some of the common causes behind the RPC error 1722 include:

• Link-local failure
• DNS failure
• DHCP failure
• WINS failure
• IPSec / Network authentication failures
• Routing failure
• Resource limitations
• Higher layer protocol is returning this error
• Higher layer protocol not running

AD replication error 1722 Troubleshooting Tips

Fortunately, our Support Team has come up with this exhaustive list of troubleshooting tips to help resolve the issue on hand.

• Check if the service status and startup value are correct for RPC Locator, RPC, and Kerberos Key Distribution Center.
• Ensure the ClientProtocols key exists at HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc, and also contains the right default protocols.
• Moreover, verify DNS is working.
• Check if network ports are blocked by a third-party application or a firewall listening on the required ports.
• In some cases, UDP fragmentation can result in replication errors that appear to have a source of RPC server is not available.
• Furthermore, check for SMB signing mismatches between DCs

In addition, our Support Techs suggest trying each of the above suggestions to resolve AD replication error 1722. However, if you are still having trouble, give us a call.

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Conclusion

To sum up, our skilled Support Engineers at Bobcares demonstrated how to resolve AD replication error 1722.