DNS_ERROR_NON_RFC_NAME - 9556 (0x2554)
DNS name does not comply with RFC specifications.
Updated: Feb 21, 2026
Introduction
This article provides a detailed technical reference for the DNS_ERROR_NON_RFC_NAME error code, which is returned by Windows APIs related to Domain Name System (DNS) operations. The error indicates that a DNS name does not adhere to the requirements specified in relevant Request for Comments (RFCs).
Technical Meaning
The DNS_ERROR_NON_RFC_NAME error code signifies that a DNS name provided during an operation did not conform to the standards outlined in the applicable RFC documents. This can include issues such as incorrect character usage, invalid domain labels, or other non-compliant naming conventions.
Error Details
When this error is encountered, it typically indicates that the input DNS name does not meet the necessary criteria for valid DNS names as defined by the relevant RFCs. Common issues might involve the use of characters not allowed in DNS names, incorrect label length, or improper domain structure.
Usage Context
This error can occur in various Windows API functions related to DNS operations, such as DnsQuery, DnsGetHostByName, and others that validate or resolve DNS names. It is important for developers to ensure that the input provided to these APIs complies with the specified naming conventions.
Developer Interpretation
Developers should interpret this error as an indication that the DNS name passed to a function does not conform to the standards defined in relevant RFCs. This can affect operations such as domain resolution, host lookup, and other DNS-related tasks. Ensuring that all input names adhere to these standards is crucial for avoiding this error.
Related Errors
DNS_ERROR_NAME_DOES_NOT_EXIST: Indicates that a requested name does not exist in the DNS system.DNS_ERROR_NO_SUCH_DOMAIN: Similar toDNS_ERROR_NAME_DOES_NOT_EXIST, but specifically related to domain-level issues.ERROR_INVALID_PARAMETER: A generic error indicating an invalid parameter was passed, which could include non-compliant DNS names.
FAQ
Q: What does the DNS_ERROR_NON_RFC_NAME error mean?
A: It indicates that a provided DNS name did not comply with the requirements specified in relevant RFCs. Ensure your input adheres to these standards.
Q: How can I avoid this error?
A: Validate all DNS names before passing them to Windows APIs and ensure they conform to the applicable RFC specifications.
Summary
The DNS_ERROR_NON_RFC_NAME error code is a specific technical indicator that a provided DNS name does not comply with the standards defined in relevant RFCs. Developers should take care to validate input names to avoid this error, ensuring smooth operation of DNS-related functions in their applications.