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IJ52871: DUPLICATE UDP SOCKETS CAN GET CREATED CAUSING CONNECTION ISSUES APPLIES TO AIX 7200-05

 

APAR status

  • Closed as program error.

Error description

  • This issue was discovered in an Oracle RAC environment
with HAIP configuration where this was leading to Oracle
DB crashes.

It is not exclusive to this environment, but it is more
common there because the issue can occur in situations
where the same IP is removed from a particular interface
and then re-configured on the same interface shortly
afterwards. This is something the HAIP configuration for
Oracle does by design, but other applications or scripts
can also cause it.

When this scenario occurs and old active sockets remain
prior to removing the IP, then new sockets start getting
opened after re-configuring the IP, these sockets can
sometimes be identical.

This can lead to UDP packets being received on the wrong
sockets from the application perspective and eventually
to these connections timing out, since the application is
 unable to receive the packets for the correct socket and
 they get stuck in the wrong socket Recv-Q.

Local fix

  • No local fix or workaround exists for this issue, an ifix
needs to be installed or AIX updated to a SP that
contains the fix.

Problem summary

  • Same ephemeral port may get allocated to multiple sockets when
socket is created with IP_EXPAND_EPHEMERAL flag. This may cause
data not to be delivered to the correct socket and may cause
applications like oracle to misbehave. This may happen when
an IP address is moved from one interface to another interface
or when IP addresses of multiple interfaces are swapped

Problem conclusion

  • Code is modified to allocate the source ports from given
ephemeral port ranges and avoided the duplicate source port
allocation between sockets created with IP_EXPAND_EPHEMERAL
flag

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IJ52871
    • 

  • Reported component name
    AIX V7.2
    • 

  • Reported component ID
    5765CD200
    • 

  • Reported release
    720
    • 

  • Status
    CLOSED  PER
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2024-10-21
    • 

  • Closed date
    2024-11-12
    • 

  • Last modified date
    2025-12-10
    • 






Fix information


    

  • Fixed component name
    AIX V7.2
    • 

  • Fixed component ID
    5765CD200
    • 



Applicable component levels


    








      
              
                            

              

              [{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SG11S","label":"AIX 7.2 HIPERS- APARs and Fixes"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"720","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]
              

                                                                    

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            10 December 2025
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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