ERROR_IPSEC_IKE_NEG_STATUS_EXTENDED_END - 13909 (0x3655)
Updated: Feb 21, 2026
Technical Meaning
This error code, ERROR_IPSEC_IKE_NEG_STATUS_EXTENDED_END, is a specific return value indicating an extended negotiation failure in the Internet Protocol Security (IPsec) and Internet Key Exchange (IKE) protocols. It signifies that the key exchange process has encountered an issue that cannot be resolved by standard mechanisms.
Error Details
The ERROR_IPSEC_IKE_NEG_STATUS_EXTENDED_END error is returned when the IPsec/IKE negotiation fails in a manner that requires additional information to diagnose and resolve the problem. This typically occurs during the initial phase of establishing a secure connection, where the protocols attempt to negotiate security parameters such as encryption algorithms, key exchange methods, or other critical settings.
Usage Context
This error is commonly encountered when configuring or troubleshooting IPsec/IKE connections in Windows environments. It may be returned by various components within the Windows Security subsystem that handle IPsec/IKE operations, including the Network Policy Server (NPS) and the Local Security Authority Subsystem Service (LSASS).
Developer Interpretation
Developers should interpret this error as an indication of a complex negotiation failure that requires further investigation. The specific cause may not be immediately apparent from the error code alone, necessitating additional diagnostic steps to identify the root issue.
Related Errors
ERROR_IPSEC_IKE_NEG_STATUS_BEGIN(13904): Indicates the start of an IKE negotiation failure.ERROR_IPSEC_IKE_NEG_STATUS_END(13908): Indicates a general IKE negotiation failure, but does not specify extended issues.
FAQ
Q: What does ERROR_IPSEC_IKE_NEG_STATUS_EXTENDED_END mean?
A: It indicates that an extended negotiation failure has occurred during the IPsec/IKE key exchange process. Further investigation is required to determine the exact cause.
Q: How can I troubleshoot this error?
A: Review the detailed logs and event records for more specific information about the failure, as additional context may be provided in these sources.
Summary
ERROR_IPSEC_IKE_NEG_STATUS_EXTENDED_END is a specific return code indicating an extended negotiation failure during IPsec/IKE key exchange. Developers should interpret this error as requiring further investigation to identify and resolve the underlying issue.