OA42734: REPETITIVE ABEND0C4 IN ISTAUCPF 13/07/08 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• During inactivation of a large EE XCA line group,
  repetitive S0C4 abends are taken in module ISTAUCPF when
  attempting to remove an AUNCB from the IPNCB_LINE_LIST queue.
  The abends occur because AUNCBs have previously been
  deallocated without removing them from this list.
  
  Other symptoms include:
    ABEND0C4 in ISTMGCEE
    ABEND0C6 in ISTTSCCN
  Add keywords: overlay overlaid
  
  Verification steps:
    See if any ISTAUNCB control blocks on the IPNCB_LINE_LIST
  queue have NCBUSECT = 0 and NCBRDTE = 0.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 12 and 13 SNA: *
  *                 Enterprise Extender                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: Various symptoms after application of:  *
  *                      OA40347/UA66722 - R1D0                  *
  *                      OA41280/UA67884 - R1C0                  *
  *                                                              *
  *                      Incorrect IP routes were taken for      *
  *                      some EE datagrams over port 12000.      *
  *                      This may lead to unexpected connection  *
  *                      disconnects or the inability to         *
  *                      establish a connection.                 *
  *                                                              *
  *                      Storage growth in TCPIP private in      *
  *                      subpool 249 key6. The storage growth    *
  *                      occurs when a failure occurs trying to  *
  *                      establish a dynamic on-demand VPN       *
  *                      for EE traffic enabled for IPSEC.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  This APAR corrects multiple problems related to Enterprise
  Extender.
  
  A) OA40347/OA41280 error description (R1D0/R1C0):
  
  BACKGROUND:
  
  OA40347/OA41280 introduced code in the SNA stack to better
  handle large volumes of Enterprise Extender (EE) signals which
  flow over port 12000.  Signal traffic includes flows which
  establish, test and disconnect EE connections.  The change
  introduced by OA40347/OA41280 caused an incompatibility with
  the TCPIP stack which handles EE traffic.  This incompatibility
  does not directly affect HPR/RTP traffic which utilizes EE ports
  12001 through 12004.  The incompatibility occurs when two or
  more EE connections, associated with the same local VIPA,
  simultaneously transmit signal data concurrently.  z/OS CS
  configurations with larger numbers of EE connections may
  have a higher chance of experiencing problems due to this
  incompatibility.
  
  SYMPTOMS:
  
  1. All Enterprise Extender installations:
  
     Port 12000 traffic (i.e. XIDs, Tests) being routed outbound
     over an incorrect or non-preferred interface.  This may lead
     to packets for Port 12000 traffic being discarded and
     potentially dropped. This may show up as EE connection
     establishment problems, or EE connections unexpectedly
     dropping due to dropped packets.
  
  2. When Enterprise Extender is also configured with IPSECURITY:
  
     Storage growth in TCPIP private in subpool 249 key6. The
     storage growth occurs when a failure occurs trying to
     establish a dynamic on-demand VPN.
  
  
  B) OA41284 error description (R1D0 only):
  
  BACKGROUND:
  
  OA41284 added code to allow EE XCA groups to be defined and
  activated with large numbers of EE lines under a single group.
  An error exists within the code supplied for OA41284. This error
  causes incorrect processing to occur when an EE link is taken
  down due to a data or link INOP condition.  These INOPs can
  occur for various reasons:
    - Too many EE test (keepalive) flows are detected from a
      partner
    - Unexpected EE connectivity test failure (EEDIAG)
  
  Exposure allows freed EE lines control blocks (ISTAUNCBs) to
  still be chained on the port (VIPA) control block (IPNCB).
  This can lead to various abends when accessing the
  IPNCB_LINE_LIST which is now corrupted.
  
  SYMPTOMS:
  
  FFST probe ISTAUC01 issued by module ISTAUCPF while processing
  link (NCBLINOP) or data (NCBDINOP) for an EE line.
  
  Recursive ABEND0C4s in ISTAUCPF after V NET,INACT of XCA major
  node or XCA group, or while stopping the TCPIP stack (P TCPIP)
  
  ABEND0C4 or infinite loop in ISTNOCEE after D NET,EE command
  
  Since the storage for an ISTAUNCB is mismanaged, this may lead
  to random overlays of storage, should the storage be reused
  by another VTAM process.  The symptoms for these random overlays
  are unpredictable and may cause system instability until the
  PTF for this APAR is installed.
  

Problem conclusion

• A) OA40347/OA41280 RESOLUTION:
  
  * The PTF for TCPIP APAR PM91713 must be installed before or
    concurrently with the PTF for this APAR.
  
  * The PTF for TCPIP APAR PM91713 must be installed if
    either PTF UA66722 (APAR OA40347) or PTF UA67884
    (APAR OA41280) are already installed. An incompatibility
    exists in z/OS CS until this action is performed.
  
  
  B) OA41284 RESOLUTION:
  
  ISTAUCPF - has been corrected to recognize the input
             passed during a data or link INOP for an EE line.
  
  ISTAUCLA - has been changed to pass the AUNCB ptr in the RUPE
             (RUPEUSR) passed to ISTAUCLA.
  Note: The fix for this APAR has been logically routed
  to V2R1 569511701 (R210) via development APAR
  OA42870.
  

Temporary fix

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

Comments

APAR Information

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

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

  UA70117 UA70118

Modules/Macros

• INNERMAP ISTACCGP ISTACCG1 ISTACCSB ISTACMDT
  ISTAUCAL ISTAUCCL ISTAUCDL ISTAUCEH ISTAUCFT ISTAUCIL ISTAUCIR
  ISTAUCIS ISTAUCKI ISTAUCLA ISTAUCLF ISTAUCOA ISTAUCPF ISTAUCTM
  ISTAUCUL ISTAUCVR ISTAUNCB ISTAUVT  ISTCLW   ISTDECK1 ISTINCIC
  ISTINCON ISTINM01 ISTIPNCB ISTNCSPL ISTRAFME ISTRAFM1 ISTRLN
  ISTTSCRG ISTTSCWU ISTTSC89 IUTRPNEE
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R1C0 PSY UA70117

     UP13/09/05 P F309 «

• R1D0 PSY UA70118

     UP13/09/05 P F309 «

Fix is available

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