OW03031: HIERARCHY VIOLATIONS CAUSE SESSION FAILURE (SENSE 08900022)

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible.

Error description

• HIERARCHY VIOLATIONS CAUSE SESSION FAILURE
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of VTAM V4R1 as an APPN Network        *
  *                 Node attaching to a VTAM V4R2 Border         *
  *                 Node.                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: This problem may occur when a V4R2      *
  *                      Border Node attaches to a V4R1          *
  *                      Network Node, and presents an EN        *
  *                      image to the V4R1 Network Node. Since   *
  *                      the V4R2 EN is really a Border          *
  *                      Node, there were cases where the BN     *
  *                      was claiming ownership of a resource    *
  *                      that was another EN. This was           *
  *                      causing a hierarchy violation in the    *
  *                      V4R1 NN during session setup,           *
  *                      (sense code 08900022 - destination      *
  *                      not served by this CP). It appeared     *
  *                      to the NN that an ENCP owned another    *
  *                      ENCP.                                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The resource hierarchy problems are caused as follows:
  If 3C information is received from an end node,
  a 3C with resource identifier F6 (NNCP) is only allowed
  if that 3C matches our CP name. If an end node happens to
  put some other name as a network node 3C, SSL does
  not assume the correct node roles.  Therefore these
  situations should be flagged in DS as protocol
  violations, or corrected by DS.
  
  There are basically 2 problems in DS where it is not
  handling these hierarchy problems.
  
  a) A border node saying it's an end node may be forwarding a
     request which contains resource information indicating a
     sole CV3D (ENCP). This would be the case if the resource
     being searched for was actually an EN CP served by the
     V4R2 Border Node. The sole CV3D (ENCP) contains the CP
     name of the EN owned by the V4R2 Border Node. The Network
     Node must cache this information as a subordinate resource
     of the served end node (the V4R2 Border node) for DS routing
     to work properly. However, since the 3D resource itself is an
     ENCP, this may cause an invalid hierarchy with an ENCP
     owning an ENCP.
  b) Also, if an end node has a problem where it sends network
     node hierarchy on the request or response to its server,
     VTAM was honoring this information as valid, and was
     choosing the wrong OLU/DLU fsm in SSL, as well as other
     varying problems.
  

Problem conclusion

Temporary fix

Comments

• To handle the hierarchy violation problems:
  1) To handle the case where a border node can
     indicate that it as an ENCP owns another ENCP, code was
     added to ISTDRSCA. When DRSCA is executed in a Network Node
     and a local end node (in particular, when the local end node
     is a VTAM Border node) assumes ownership of resources found
     through it, the Network Node downgrades the resource type
     to LU.
  
  2) To handle the case where an EN sends a bad network node
     hierarchy on the request or response to its server, code
     was added to ISTDRFVH to verify that if hierarchy was
     received from an end node, that either no NN information is
     present, or that the NN information matches our node name.
     Now, a CPRC will be cut and an alert generated if NN
     hierarchy is from an end node which does not name this
     node as the NN.
  

APAR Information

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

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

  UW13300

Modules/Macros

• ISTDRFVH ISTDRSCA ISTDRSNN
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R101 PSY UW13300

     UP95/04/07 P F504

Fix is available

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