PM36103: MULTIPLE STACKS NOT COMMUNICATING VIA IUTSAMEH CAUSING PING TIMEOUTS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• There is a timing issue where one stack received a DM_ACT_IND,
  and sends data before the other side received the DM_ACT_IND.
  When the DM_ACT_IND finally arrives we have already transitioned
  to state 8 which is determined to be an invalid state for the
  DM_ACT_IND.
  
  
  
  Verification Steps:
  
  1. In a 4 stack environment, one stack is missing a "EZZ4324I
  CONNECTION TO 192.168.250..." message, the other 3 stacks get
  all three. When working correctly all 4 stacks should get 3
  "EZZ4324I CONNECTION TO 192.168.250..." messages.
  
  
  2. Ctrace (Options=Vtam) show the following exception record...
  "!Wrong State for input signal"
  
  3. Ctrace shows connection currently in state 8 (connection
  active)
  
  4. Ctrace show stack receiving MPC Register IP Address command
  before receiving DM_ACT_IND.
  
  
  
  
  
  Keywords:
  
  DM_ACT_REQ, DM_ACT_CNF, RegIP, Start IP, CM_Connect_IND
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 10, 11, 12     *
  *                 and 13 IP:                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: IUTSAMEH connection is not activated    *
  *                      between multiple stacks.                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During the activation of multiple TCPIP stacks on the same host,
  the IUTSAMEH MPC Register IP Command signal may arrive after
  the Device Management Activate Indicator signal. This will
  cause the samehost connection between two stacks to not
  activate.
  +-------------------------------------------------------------+
  + 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

• EZBIFCPP has been modified to activate the samehost connection
  regardless of the arrival order of the MPC Register IP Command
  and Device Management Activate Indicator signals.
  
  * 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:

  UK67462 UK67464 UK67463 UK67465

Modules/Macros

• EZBIFCPP
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1A0 PSY UK67462

     UP11/06/22 P F106

• R1B0 PSY UK67463

     UP11/06/22 P F106

• R1C0 PSY UK67464

     UP11/06/22 P F106

• R1D0 PSY UK67465

     UP11/06/22 P F106

Fix is available

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