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IV95637: LNCENTDD IS DROPPING LARGESEND PACKETS APPLIES TO AIX 7100-04 17/09/29 PTF PECHANGE

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APAR status

  • Closed as program error.

Error description

  • **************************************************************
    * USERS AFFECTED:
    * Systems running the AIX 7100-04 Technology Level
    * with devices.ethernet.lnc.rte at the 7.1.4.31 level.
    **************************************************************
    * ERROR DESCRIPTION:
    * In the latest SPs, for certain adapters, VLAN tagged
    * largesend packets are silently dropped in the AIX/VIOS
    * adapter layer.
    *
    * On all AIX and VIOS levels mentioned above, adapters using
    * the lncentdd driver are exposed.
    * On 7100-03-09, adapters using the mlxentdd driver are also
    * exposed.
    *
    * Find out if a system has any adapters using an affected
    * driver with lsdev, for example:
    * # lsdev -F "name ddins" | grep lncentdd
    * Note: on a VIOS, this must be run as root using
    * 'oem_setup_env'.
    **************************************************************
    * RECOMMENDATION:
    * Install APAR IV95637.
    * Prior to fix availability, an interim fix is available from
    * either
    * ftp://aix.software.ibm.com/aix/ifixes/iv95637/
    * https://aix.software.ibm.com/aix/ifixes/iv95637/
    * Installation of the ifix requires a reboot.
    **************************************************************
    

Local fix

  • Disable largesend on the physical adapter:
    chdev -a large_send=no -l entX
    

Problem summary

  • The driver incorrectly calculates the packet header size for
    VLAN tagged
    largesend packets and therefore the packets are silently dropped
    

Problem conclusion

  • Correct the code to properly handle VLAN tagged largesend
    packets
    

Temporary fix

  •   *********
      * HIPER *
      *********
    

Comments

  • 7100-04 - use AIX APAR IV95637
    

APAR Information

  • APAR number

    IV95637

  • Reported component name

    AIX V7.1

  • Reported component ID

    5765H4000

  • Reported release

    710

  • Status

    CLOSED PER

  • PE

    YesPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-05-02

  • Closed date

    2017-05-03

  • Last modified date

    2017-09-29

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

    IV95372

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

Fix information

  • Fixed component name

    AIX V7.1

  • Fixed component ID

    5765H4000

Applicable component levels

  • R710 PSY U873670

       UP17/09/22 I 1000 Ž

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Document Information

Modified date:
20 April 2022