What does Windows error code 9751 (DNS_INFO_AXFR_COMPLETE) mean?

DNS_INFO_AXFR_COMPLETE

DNS AXFR (zone transfer) complete.

DNS_INFO_AXFR_COMPLETE is Win32 error 9751 (0x00002617).

Likely impact: Blind retries can waste bandwidth and obscure a successful transfer.

Typical causes

• this is normally a completion status rather than an error.
• a wrapper classifies every nonzero value as failure.
• the transfer completed but post-validation still fails.
• telemetry loses the zone serial and source server.

Troubleshooting steps

1. Verify that the receiver has processed the complete AXFR sequence and can validate the resulting zone.
2. Collect zone name and serial and primary and secondary identities.
3. Correlate record count and transfer timestamps with the DNS Server event log, DNS analytical logging when enabled, packet capture, zone metadata, server configuration, and the exact DNS API request.

Useful evidence

• Collect SOA before and after.
• Collect post-transfer zone-load result.

Recovery and retry

Record the transfer as complete, then validate SOA serial, zone load, and serving behavior rather than retrying solely because the status is nonzero.

Related errors

DNS_ERROR_AXFR reports a failed transfer; this informational code reports completion

Example

A transfer worker returns 9751 and a generic wrapper marks it failed. Domain-aware handling recognizes completion and verifies the loaded serial.

References

• Microsoft: exact Win32 system error range
• Microsoft: DNS server troubleshooting
• Microsoft: DNS logging and diagnostics