PI05549: IWQ TRAFFIC IS SENT TO AN INCORRECT STACK WHEN THE OSA IS SHARED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• IWQ data traffic is forwarded to an incorrect stack when the OSA
  card is shared between the sysplex distributor stack and the
  target stack.
  

Local fix

• There are several workarounds for this problem:
  1. Disable IQDIO inbound workload queueing
  2. Take out the VIPAROUTE statement so that distributed traffic
  will be sent to the target stack via XCF link instead of the
  shared OSA
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release 13 IP:            *
  *                 QDIO Inbound Workload Queueing (IWQ)         *
  *                 for sysplex distributor (SD)                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: TCP connection hangs after bulk data    *
  *                      detected.                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An OSA card is shared between two TCPIP stacks.  One of the
  stacks is the distributor for a DVIPA and the other stack is
  a target for the DVIPA. The OSA is configured with QDIO
  Inbound Workload Queueing(IWQ) on both TCPIP stacks.  A TCP
  connection is distributed to the target stack.  TCPIP detects
  the connection is operating in bulk-data fashion and the
  connection is registered with the OSA. Future inbound
  packets are sent directly to the target. The target does
  not accept packets for distributed DVIPAs except
  from the distributor.  The packet is forwarded to the
  distributor, but the OSA redirects the packet to the
  target stack again.  This causes a loop forwarding the
  packet and the TCP connection hangs.
  +-------------------------------------------------------------+
  + Please check our Communications Server for OS/390 homepages +
  + for common networking tips and fixes.  The URL for these    +
  + homepages can be found in Informational APAR II11334.       +
  +-------------------------------------------------------------+
  

Problem conclusion

• TCPIP is updated to accept packets for a DVIPA when the
  connection is established and in the dynamic VIPA connection
  routing table.
  
  OSA Express 4S, OSA Express 5S
  D/T2817
  D/T2818
  D/T2827
  D/T2828
  
  * Cross Reference between External and Internal Names
  

Temporary fix

Comments

APAR Information

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

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

  PI07587 UI13487

Modules/Macros

• EZBIPINB EZBXFUT3 EZBX6UT3 EZB2IUDR EZB6PINB
  TPSTMSG1
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1D0 PSY UI13487

     UP14/01/22 P F401

Fix is available

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