OA15348: EE CONNECTION HANGS IN PCTD2 STATE AFTER AN IST680I FAILURE FOR THE CONNECTION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• EE connection hangs in PCTD2 state after an IST680I
  failure for the connection. Trace shows after an exchange
  of pre-negotiation XIDs, VTAM sent a DISCONNECT. VTAM did
  not wait for the response to clean-up that connection - which
  resulted in PCTD2 state when a subsequent XID was received.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All using Enterprise Extender (EE) with      *
  *                 Extended Border Node (EBN) configurations.   *
  ****************************************************************
  * PROBLEM DESCRIPTION: EE switched PU hangs PCTD2 after        *
  *                      REQCONT failed.                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem is summarized as follows:
  
  1) VTAM (EBN) is attempting to dial-out an EE connection
     to a cross-net host.
  2) VTAM initiates the dial with an XID3 pn (req).
  3) The EE partner returns an XID3 pn (rsp) to VTAM.
  4) A REQCONT (req) is sent to PUNS to initiate contact.
  5) The REQCONT is forwarded to CFGSVCs for processing.
  6) Module ISTACCQ3 calls module ISTACCRE to validate
     the incoming NETID.
  7) Module ISTACCRE fails the NETID verification and
     returns processing to ISTACCQ3.
  8) ISTACCQ3 proceeds to issue the following error
     messages:
  
     IST680I CONNECTION REQUEST DENIED - ID = cpname
             INVALID NETWORK NAME
     IST1394I CPNAME = netid.cpname      STATION ID = 0200FFF1880F
     IST081I LINE NAME = line, LINE GROUP = group, MAJNOD = majnod
     IST314I END
  
     IST621I RECOVERY SUCCESSFUL FOR NETWORK RESOURCE swpuname
  
  9) Immediately following this, ISTACCQ3 sent two ABCONN requests
     to the AUNCB PU PAB to terminate the dial-out.  This is
     the root cause of the PCTD2 problem.
  10) The AUNCB PU PAB received the first ABCONN and sent an LDLC
      DISC command to the partner.  The next expected signal
      is a DM from the EE partner to acknowledge the DISC.
  11) The AUNCB PU PAB received the second ABCONN request.  This
      caused the PU PAB to cleanup the AUNCB and not wait for
      the DM from the partner.
  12) In the meantime, the partner EE node has already sent
      an XID3 np request.  This was immediately followed by
      the DM acknowledging the DISC.
  13) The XID3 np was received by ISTAUCII, the old connection
      was not longer findable (via IPTADDRS), so a new
      line (AUNCB) was assigned to this connection.
  14) A REQCONT was sent to PUNS.  The following message is issued
      to acknowledge the connection attempt:
  
      IST590I CONNECTIN ESTABLISHED FOR PU swpuname ON LINE line
  
      NOTE: At this point this looks like a DIAL-IN connection,
            when really it is a received XID3 np from the DIAL-OUT
            processing.
  15) VTAM then responds back to the XID3 np (rsp) and waits for
      the partner to respond back (no T1 timer is set since this
      is an XID response)
  16) At this point, the partner has already cleaned up its
      connection as it has already processed the DISC command.
      The XID3 rsp is simply discarded.
  17) A display of the PU name listed in the IST590I from step 14
      shows the following:
  
      d net,id=swpuname
      IST097I DISPLAY ACCEPTED
      IST075I NAME = swpuname, TYPE = PU_T2
      IST486I STATUS= PCTD2, DESIRED STATE= ACTIV
      .
      .
  18) The switched PU hangs indefinitely in PCTD2 state.  Operator
      intervention is required at this time.
  
  This APAR addresses the PCTD2 aspect of the problem, not the
  reason why the REQCONT from step 8 was rejected.
  

Problem conclusion

• Module ISTACCQ3 has been corrected to avoid sending two
  ABCONN requests during the REQCONT flow.  Boolean variables
  have been defined to indicate when an ABCONN and RESET have
  been performed.  The variables will now be checked prior
  to sending another ABCONN down the the NCB PU PAB.
  
  Module ISTAUCLA has been included for maintenance purposes.
  

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:

  UA25049 UA25050 UA25051 UA25052 OA16395

Modules/Macros

• ISTACCQ3 ISTAUCLA
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R140 PSY UA25049

     UP06/04/15 P F604

• R150 PSY UA25050

     UP06/04/15 P F604

• R160 PSY UA25051

     UP06/04/14 P F604

• R170 PSY UA25052

     UP06/04/14 P F604

Fix is available

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