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IC98630: KERBEROS TCP REQUESTS TO MIT KDC MIGHT FAIL DUE TO CONNECTION REUSE

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • On DataPower version 6.0.0, the Kerberos client attempts to
    re-use its TCP connection to the KDC when multiple rounds of
    request/response are required during a ticket fetch such as
    when pre-authentication is required. In the event that the
    KDC server does not support TCP connection reuse this might
    cause the ticket fetch and the AP-REQ token generation to
    fail.
    
    The failure looks like this in the DataPower logs:
    [0x8140001b][kerberos][error] mpgw(sample_mgw):
    tid(1234)[request][1.2.3.4]:
    get-apreq: network error receiving reply from Kerberos KDC
    
    
    The two most common KDC implementations are Microsoft Active
    Directory and MIT Kerberos.  The MIT Kerberos KDC does not
    support TCP connection reuse and triggers this problem.
    Microsoft Active Directory KDC does support TCP connection reuse
    and does not trigger this problem.  The Kerberos specification
    does not require a KDC to support TCP connection reuse, so other
    KDC implementations not mentioned here might also trigger this
    problem.
    

Local fix

  • Configure the Kerberos client to use UDP (instead of TCP) or to
    disable pre-authentication on the KDC for this principal.
    Alternatively, use a KDC that supports TCP connection reuse.
    

Problem summary

  • A DataPower Kerberos client sending an AP-REQ to an MIT KDC
    while using TCP might receive a network error.
    

Problem conclusion

Temporary fix

Comments

APAR Information

  • APAR number

    IC98630

  • Reported component name

    DATAPOWER

  • Reported component ID

    DP1234567

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-01-09

  • Closed date

    2014-03-05

  • Last modified date

    2014-03-31

  • 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

    DATAPOWER

  • Fixed component ID

    DP1234567

Applicable component levels

  • R600 PSY

       UP

  • R601 PSY

       UP



Document information

More support for: IBM DataPower Gateways
General

Software version: 6.0.0

Reference #: IC98630

Modified date: 31 March 2014