PK32248: LOOP IN EZBIPOUT WHEN ROUTES ARE INVALIDATED

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible.

Error description

• .
  The TCPIP stack is configured with MULTIPATH PERCONNECTION
  enabled.  If all of the routes for the destination being used by
  a TCP connection are invalidated (for example, multiple OMPROUTE
  adjacency failures), the potential exists for the logic to find
  an alternate route for an outbound packet in EZBIPOUT (the
  ValidateMpRoute subroutine) to get into an endless loop.  If
  this happens it is quite likely for all of the system's
  processors to become dispatched to unending SRBs, causing a
  system outage requiring an IPL.
  
  Additional Diagnostic Information:
  
     For PTF level UK04331 on z/OS 1.4, this loop will be at
     offsets +8016 to +8058.  Offsets for other PTF levels and
     releases will vary.
  
     The chain of RTEs starting at Rtp_chain@ in the current RTOP
     (pointed to by the vhead@ variable) will all have rtstate =
     RT_INACTIVE (x01).  The RTE pointed to by rtp_mpcur@ in the
     current RTOP entry will not be on the above chain.
  
                                                                 .
  

Local fix

• .
  
  Ensure all of the recommendations for OMPROUTE performance
  listed in information APAR II12026 have been followed.  This
  will significantly reduce the likelihood of multiple
  simultaneous dynamic routing failures.
  
  Specify NOMULTIPATH on the IPCONFIG statement.
  
                                                                 .
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Releases 4, 5, and 6 IP.  *
  ****************************************************************
  * PROBLEM DESCRIPTION: Loop in EZBIPOUT. TCP/IP must be        *
  *                      restarted.                              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Loop in EZBIPOUT after many, many route failures.  EZBIPOUT was
  searching for a route, but all routes were invalidated (while
  the routes were being searched) thus the loop was never exitted.
  +-------------------------------------------------------------+
  + 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

Temporary fix

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

Comments

• Module EZBIPOUT has been changed to detect this condition and
  exit the loop.
  

APAR Information

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

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

  UK19244 UK19245 UK19246

Modules/Macros

• EZBIPOUT
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R140 PSY UK19244

     UP06/11/28 P F611 Ž

• R150 PSY UK19245

     UP06/11/28 P F611 Ž

• R160 PSY UK19246

     UP06/11/28 P F611 Ž

Fix is available

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