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IV01302: KEEPALIVE PACKETS HAVE ZERO WINDOW SIZE WHEN RFC1323 IS OFF. APPLIES TO AIX 6100-07

A fix is available

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APAR status

  • Closed as program error.

Error description

  • If rfc1323 window scaling is NOT in effect AIX keepalive
    packets may have a small or zero window size even when
    the
    AIX recv-q is empty. This requires the remote side to
    send
    and process a window probe exchange before resuming
    transmission.
    

Local fix

  • Disable keepalive socket option in application or enable
    rfc1323 on both ends of connection.
    

Problem summary

  • Environment with lowered  keepalive intervals will have
    performance impact when rfc1323 scalling is disabled.
    
    If rfc1323 window scaling is NOT in effect AIX keepalive
    packets may have a small or zero window size even when
    the AIX recv-q is empty. This requires the remote side to
    send and process a window probe exchange before resuming
    transmission.
    

Problem conclusion

  • The window size is correctly advertized in all cases
    with keep alive packet. This avoids the performance issue
    created due to small window advertizement.
    

Temporary fix

Comments

  • 5300-12 - use AIX APAR IV17806
    6100-05 - use AIX APAR IV13929
    6100-06 - use AIX APAR IV14145
    6100-07 - use AIX APAR IV01302
    7100-02 - use AIX APAR IV29845
    

APAR Information

  • APAR number

    IV01302

  • Reported component name

    AIX 610 STD EDI

  • Reported component ID

    5765G6200

  • Reported release

    610

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2011-06-01

  • Closed date

    2011-06-01

  • Last modified date

    2013-04-10

Fix information

  • Fixed component name

    AIX 610 STD EDI

  • Fixed component ID

    5765G6200

Applicable component levels

  • R610 PSY U837954

       UP11/10/15 I 1000

PTF to Fileset Mapping

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Document Information

Modified date:
10 April 2013