Short answer
DNS Server Event ID 4013 indicates that DNS startup is waiting for Active Directory Domain Services initial synchronization so AD-integrated zone data can be available. A brief event during domain-controller startup can be transient. If it persists or clients lose name resolution, investigate AD replication, DC discovery, and DNS dependencies before changing synchronization behavior.
Symptoms
- DNS Server logs Event ID
4013. - AD-integrated zones are not immediately available after startup.
- Domain controllers or clients report DNS lookup failures while a DC is waiting for directory synchronization.
Exact event and evidence
Capture the full Event 4013 message and timestamp, plus relevant Directory Service and System events. The event alone does not identify the underlying replication or name-resolution fault.
Environment
Windows Server domain controllers hosting DNS with AD-integrated zones. Startup sequencing and behavior can vary by Windows Server version and domain topology.
Evidence to collect
- Determine whether the event clears after startup or repeats while DNS service remains unavailable.
- Check domain-controller discovery and replication health using supported read-only diagnostics such as
dcdiagandrepadmin. - Verify the DC can resolve required records for its replication partners and domain services, including the configured DNS client settings.
- Review AD replication errors, unreachable partners, stale DC references, and network or firewall interruptions.
- Correlate the event with reboot order and whether multiple DCs or DNS servers were unavailable at the same time.
Example read-only checks:
dcdiag /test:dns /v
repadmin /replsummary
repadmin /showreplReview output locally and redact domain names, server names, and IP addresses before sharing.
Likely cause
DNS is waiting for AD DS initial synchronization, or the DC cannot complete the expected synchronization because a replication partner or required DNS record is unavailable. Event 4013 is a startup symptom; use the surrounding directory and DNS evidence to identify the cause.
Remediation
Restore reliable DNS resolution and AD replication between healthy domain controllers. Correct DNS client configuration, replication connectivity, stale references, or startup sequencing only where the collected evidence supports it. Avoid rebooting all DCs together; preserve a reachable, healthy DNS/DC path during recovery.
Do not set Repl Perform Initial Synchronizations to 0 as a standing production fix. Microsoft warns this can cause lingering objects and is not recommended for production environments. Use only a vendor-supported, temporary recovery procedure when directed by Microsoft support and with a rollback plan.
Verification
Confirm AD replication converges, the DC advertises and resolves required domain records, AD-integrated zones load, and DNS clients resolve representative records. Monitor after a controlled restart if startup behavior was part of the incident.
Version notes
Check the linked Microsoft article against the specific Windows Server versions and topology. DNS, AD DS, and replication behavior depend on supported-version details.
Sources
Evidence status
This is an original guide based on linked Microsoft documentation. It is not a report of a field investigation or a domain-controller change tested in production.