About this tag
The KDC (Key Distribution Center) tag on WindowsForum.com covers issues related to Kerberos authentication in Windows domains. Discussions include DCDiag errors with code 0xc0000007 where the Security Account Manager fails a KDC request, and event ID 40970 indicating a downgrade attempt with encryption type not supported by the KDC, leading to Group Policy failures. Other threads address KDC Event ID 16 or 27 when DES encryption is disabled for Kerberos, and problems with S4U2Self ticket requests on Windows Server 2008 R2. These topics are relevant for IT administrators managing Active Directory and Kerberos security in Windows Server environments.
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    DCDiag error 0xc0000007 SystemLog

    Ehe Security Account Manager failed a KDC request in and unexpected way. The error is int the data field. The account name was and lookup type 0x108
    • bswhipp
    • Thread
    • authentication failure credential management domain controller error analysis error data event id event log kdc kerberos lookup type security security event security logs troubleshooting windows security
    • Replies: 1
    • Forum: Windows Server Forums
  2. B

    Windows 2025 Domain with Windows 2022 member servers loosing (Red X) on Mapped drives overnight.

    It seems to coincide with a warning on the Windows 2022 member server event ID 40970 LSA (LSASrv) The security System has detected a downgrade attempt when contacting the 3-part SPN LDAP/Domain Controller FQDN/Domain@Domain with error code "The encryption type is not supported by the KDC...
    • bswhipp
    • Thread
    • access issues authentication domain controller downgrade error codes event id file explorer group policy kdc ldap name resolution network processing failures retry security server management troubleshooting windows server workstation access
    • Replies: 3
    • Forum: Windows Server Forums