IBM Support

IT49049: SPNEGO LOAD TESTING INTERMITTENTLY FAILS WHILE NEGOTIATING NTLM AND KERBEROS AUTHENTICATION

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APAR status

  • Closed as program error.

Error description

  • During load testing, where requests randomly alternate between
    Kerberos and NTLM authentication against an IWAconfigured
    listener, some requests intermittently fail. This issue cannot
    be reproduced when service trace is enabled because the
    additional overhead slows processing enough for the
    authentication sequences to complete before the session times
    out.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    All Users of IBM App Connect Enterprise v12 and v13 using IWA
    authentication.
    
    
    Platforms affected:
    WinX64
    
    ****************************************************************
    PROBLEM DESCRIPTION:
    Intermittent authentication failures occur during load testing
    when requests rapidly alternate between Kerberos and NTLM
    against an IBM App Connect Enterprise listener configured for
    SPNEGObased IWA authentication. This issue cannot be captured
    when service trace is enabled.
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    IT49049

  • Reported component name

    APP CONNECT ENT

  • Reported component ID

    5724J0560

  • Reported release

    C00

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2026-02-10

  • Closed date

    2026-02-27

  • Last modified date

    2026-02-27

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    APP CONNECT ENT

  • Fixed component ID

    5724J0560

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSDR5J","label":"IBM App Connect Enterprise"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"C00","Line of Business":{"code":"LOB77","label":"Automation Platform"}}]

Document Information

Modified date:
27 February 2026