PH07839: IPV4 ADDRESSES CAN NOT BE COMPLETELY REPRESENTED TO WLM CLIENT IP ADDRESS (CIP) CLASSIFICATION RULES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DB2DDF DB2TCPIP Story 89500 s89500
  IPv4 addresses can not be completely represented to WLM Client
  IP address (CIP) classification rules.
  
  See APAR PH16219 for additional changes.
  
  ***************************************************************
  Additional Symptoms and Keywords:
   WLM IWM4CLSY CLIENT_IPADDR CIP Client IP address
  

Local fix

• no local workaround or fix
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All Distributed Data Facility (DDF) users.   *
  *                 Specifically those that utilize the WLM CIP  *
  *                 (Client IP address) classification rule.     *
  ****************************************************************
  * PROBLEM DESCRIPTION: IPv4 addresses can not be completely    *
  *                      represented to WLM Client IP Address    *
  *                      (CIP) classification rules.             *
  ****************************************************************
  * RECOMMENDATION: Apply corrective PTF when available          *
  ****************************************************************
  In z/OS 2.1 (or higher) environments, Db2 11 (or higher) for
  z/OS supports the ability to establish WLM service classes and
  performance goals based on the IP address of the remote client
  that's accessing Db2 as a server.  This is accomplished via
  WLM CIP (Client IP address) classification rule definitions
  in the WLM (ISPF application) classification panels.
  The user wants to exploit this ability for their IPv4 related
  client IP addresses.  However, Db2 incorrectly truncates the
  IPv4 address that's passed to the WLM classification service.
  This makes it impossible for users to establish WLM CIP
  classification rules, and hence the desired service class
  performance goals, based on the remote client's complete IPv4
  address.
   Note: Establishing WLM CIP classification rules relative to
    remote client IPv6 addresses is not an issue because Db2
    does pass the entire (uncompressed) IPv6 address to the WLM
    classification service.
  

Problem conclusion

• Db2 has been changed to pass a complete IPv4 address to the
  WLM classification service.
   Note: Nothing is changed relative to IPv6 addresses.
  
  Db2 documentation changes are necessary to provide guidance on
  how the WLM CIP classification value should be defined relative
  to Db2 environments.  The (Db2) description of the WLM CIP
  classification attribute is changed as follows:
  ***************************************************************
  CIP
  The client IP address for 39 characters.  This attribute can
  be used for DB2 and DDF subsystem types.
  Db2 provides WLM with the IP address in IPv6 colon-hexadecimal
  form, for both IPv4 and IPv6 addresses.  The value that Db2
  provides to WLM will essentially be an uncompressed version of
  the (compressed) value that is provided in the Db2 -DISPLAY
  THREAD and -DISPLAY LOCATION command reports and the
  SYSIBM.CLIENT_IPADDR special register.  Uncompressed values are
  provided to WLM in order to help reduce the number of
  classification rules that may be necessary since each of the
  segments of an IPv4 or IPv6 address will always have the same
  position, hence simplifying the effort of defining
  classification rules based on subnet addresses.
  For IPv4 addresses, Db2 provides an uncompressed representation
  of the dotted decimal portion of the IP address as right
  justified (leading blanks) in a 39-character space.  Right
  justification is provided for the benefit of common WLM
  definitions of IPv4 addresses in TCP/IP single-mode or
  dual-mode stack environments since the dotted-decimal portion
  of the IPv4 address will always have the same position.  The
  leading zeroes, to the dotted decimal portion, are represented
  by the IPv6 colon-hexadecimal double colon ("::") compression
  convention.
  For IPv6 addresses, Db2 provides a 39-character uncompressed
  representation of the IPv6 address.
  Examples:
  WLM value (39 character space)            Comments
  ----------------------------------------- -------------------
  "                      ::111.112.113.114" Single-mode IPv4
  "                 ::FFFF:111.112.113.114" Dual-mode IPv4
  "                      ::001.000.013.114" Single-mode IPv4
  "                 ::FFFF:001.000.013.114" Dual-mode IPv4
  "1111:2222:3333:4444:5555:6666:7777:8888" IPv6 address
  "1080:0000:0000:0000:0008:0800:200C:417A" IPv6 address
  ----------------------------------------- -------------------
  **************************************************************
  IBM Knowledge Center is updated for this change:
  http://www.ibm.com/support/knowledgecenter/SSEPEK
  
  Due to the unpredictable nature of the IPv4 address
  information that is currently passed to WLM, and the fact that
  IPv4 addresses cannot be fully represented, it is unlikely that
  any users are actually using IP addresses to influence their
  WLM service class and performance goals.  However, information
  is provided to help users determine if they are affected and,
  if so, offers a transitional technique that can be adopted in
  order to deploy the change.
  
  WARNING WARNING WARNING
  A potential incompatible change exists if, and only if, the
  WLM CIP classification rule is utilized relative to
  Subsystem_Type DDF.  Action may be necessary before this
  APAR/PTF change is applied.
  In order to determine if you're affected, enter the WLM ISPF
  application and enter the following:
   2 (extract definition from WLM couple data set)
   6 (classification rules)
   4 (browse) Type DDF
  Look for any CIP (Qualifier type) rules.
  
  If CIP rules DO NOT exist, you are not affected and no further
  action is necessary (you may stop reading).
  
  If any CIP rules do exist, you should take action BEFORE
  applying this APAR/PTF change otherwise unexpected WLM service
  class performance goals may be established for DDF server
  threads (DBATs).
  The APAR/PTF change alters the CIP value that is passed to WLM
  for remote client IPv4 (dotted-decimal) addresses.  Old CIP
  rules will therefore not be recognized once the APAR/PTF change
  is applied.  A transitional strategy can be adopted by adding
  new (additional) CIP rules based on the new CIP value that is
  passed to WLM (see the APAR/PTF information for a description
  of the new value that is passed to WLM).  The old rules will
  therefore continue to be utilized for the benefit of Db2
  systems that do not yet have the APAR/PTF change applied, and
  the new rules will be utilized for the benefit of Db2 systems
  that do have the APAR/PTF change applied.  Once the APAR/PTF
  change has been fully deployed, the old CIP rules can then be
  removed as opportunity permits.
  

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:

  UI61648 UI61652

Modules/Macros

•    DSNLILNR
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RB10 PSY UI61652

     UP19/03/19 P F903

• RC10 PSY UI61648

     UP19/03/19 P F903

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.