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IZ94528: DUPLICATE SYN PACKETS CAUSE SOCKETS TO NEVER BE FREED APPLIES TO AIX 6100-06

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APAR status

  • Closed as program error.

Error description

  • There are two symptoms for this.  One is that memory will
be used up and eventually network memory will be
exhausted.
The list of sockets of the free list will be large --
often
in the hundreds of thousands.  The other symptom is the
statistic: "Connection dropped due to duplicate SYN
packets" will be large.  Usually it is zero.  Note that
if
the system freezes and is rebooted, this count will be 0
so in the snap it will be 0.  But issuing netstat -s
using
kdb from a dump of the system will provide the value at
the time the system dump was forced (assuming a system
dump is forced).

Local fix

  • 



Problem summary


    

  • Customer system freezes. The network memory is exhausted and
also the statistic: "Connection dropped due to duplicate SYN
packets" was very large ( 744204).

    



Problem conclusion


    

  • When we identify a packet as duplicate SYN and before
dropping it, we will unref the socket ( of existing
connection). Later when socket is closEd it will get closed
without any issue.

    



Temporary fix


    

  • 



Comments


    

  • 5300-10 - use AIX APAR IZ83149
5300-11 - use AIX APAR IZ91126
5300-12 - use AIX APAR IZ91125
6100-03 - use AIX APAR IZ94544
6100-04 - use AIX APAR IZ94537
6100-05 - use AIX APAR IZ94531
6100-06 - use AIX APAR IZ94528
6100-06 - use AIX APAR IZ86972
7100-01 - use AIX APAR IZ99505

    



APAR Information




    

  • APAR number
    IZ94528
    • 

  • Reported component name
    AIX 610 STD EDI
    • 

  • Reported component ID
    5765G6200
    • 

  • Reported release
    610
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Submitted date
    2011-02-06
    • 

  • Closed date
    2011-02-06
    • 

  • Last modified date
    2013-04-17
    • 





    

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

    
IZ81013
    

    • 

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

    • 



Fix information


    

  • Fixed component name
    AIX 610 STD EDI
    • 

  • Fixed component ID
    5765G6200
    • 



Applicable component levels


    

  • R610  PSY  U838336
       UP11/03/21  I  1000
    • 



PTF to Fileset Mapping








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            17 April 2013
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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