ERROR_IPSEC_IKE_SIMULTANEOUS_REKEY - 13821 (0x35FD)
Simultaneous rekeys were detected.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_IPSEC_IKE_SIMULTANEOUS_REKEY error code indicates that a simultaneous rekeying event was detected during the operation of Internet Protocol Security (IPsec) or Internet Key Exchange (IKE). This typically occurs when there is an attempt to renegotiate security associations while existing ones are still in use.
Error Details
The numeric value 13821 and its hexadecimal representation 0x35FD uniquely identify this error. The detection of a simultaneous rekeying event can have implications for the stability and performance of IPsec/IKE operations, as it may indicate an issue with key management or negotiation processes.
Usage Context
This error is relevant in scenarios where IPsec/IKE security associations are being dynamically managed. It could be encountered during the establishment or renegotiation of secure connections over IPsec tunnels or when IKE peers exchange messages to update cryptographic keys and parameters.
Developer Interpretation
Developers should interpret this error as an indication that a rekeying event is occurring simultaneously with another operation, which may disrupt ongoing security associations. This can lead to potential issues such as data loss, connection interruptions, or increased latency due to the need for key renegotiation.
Related Errors
ERROR_IPSEC_IKE_NEGOTIATION_FAILED(13820, 0x35F6): Indicates a failure in the negotiation process of IPsec/IKE.ERROR_IPSEC_IKE_NO_CERT(13824, 0x35FE): Suggests that no certificate was found during the IKE negotiation.
FAQ
Q: What does the ERROR_IPSEC_IKE_SIMULTANEOUS_REKEY error mean?
A: It indicates a simultaneous rekeying event detected during IPsec/IKE operations, which can disrupt ongoing security associations and may require corrective action.
Q: How should I handle this error in my application?
A: Review the context of the operation that triggered the rekeying event. Ensure that all necessary parameters are correctly set and that there are no limitations or constraints being violated.
Summary
The ERROR_IPSEC_IKE_SIMULTANEOUS_REKEY error code is a specific technical indicator used in Windows systems to denote simultaneous rekeying events during IPsec/IKE operations. Developers should be aware of this error's implications and take appropriate measures to ensure the stability and security of their applications.