PM29217: MULTIPLE VIPARANGE STATEMENTS WITH OVERLAPPING SUBNETS MIGHT CONTRIBUTE TO INCORRECT VIPARANGE STATEMENT SELECTIONS

APAR status

• Closed as fixed if next.

Error description

• When multiple VIPARANGE statements are coded with overlapping
  subnets and various property values, wrong VIPARANGE statement
  with undesirable properites might be selected for a bind/ioctl
  DVIPA that gets created. For example, using last octet to
  overlap the subnets:
  
  VIPARANGE DEFINE MOVEABLE NONDISRUPTIVE 255.255.255.0  9.1.1.0
  VIPARANGE DEFINE MOVEABLE DISRUPTIVE  255.255.255.128  9.1.1.128
  VIPARANGE DEFINE MOVEABLE DISRUPTIVE  255.255.255.192  9.1.1.192
  
  A DVIPA with IP address 9.1.1.187 will match the first VIPARANGE
  statement, not the second one which is a more specific match.
  The third one will not fit because it is too specific. In this
  case, the DVIPA will be marked NONDISRUPTIVE, not DISRUPTIVE.
  

Local fix

• Arrange the VIPARANGE definitions from most specific to least
  specific. For example:
  
  VIPARANGE DEFINE MOVEABLE DISRUPTIVE  255.255.255.192  9.1.1.192
  VIPARANGE DEFINE MOVEABLE DISRUPTIVE  255.255.255.128  9.1.1.128
  VIPARANGE DEFINE MOVEABLE NONDISRUPTIVE 255.255.255.0  9.1.1.0
  
  KEYWORDS:
  VIPARANGE DVIPA IOCTL BIND DISRUPTIVE NONDISRUPTIVE
  MODDVIPA
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 10, 11 and 12  *
  *                 IP: DVIPA                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Overlapping dynamic VIPA VIPARANGE      *
  *                      addresses may result in unexpected      *
  *                      dynamic VIPA characteristics.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During a dynamic VIPA activation request the first
  VIPARANGE DEFINE statement with an address range matching the
  VIPA address will be selected.
  If multiple VIPARANGE DEFINE statements define overlapping
  address ranges, they will be searched in the order they were
  defined. If a VIPARANGE DEFINE with a more general address range
  is defined before a more specific address range, the more
  general address range definition will be selected. This may
  cause an unintended VIPARANGE definition to be selected.
  +-------------------------------------------------------------+
  + 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

Comments

• This APAR is being closed FIN (Fixed If Next) with concurrence
  from the submitting customer. This means that a fix to this
  APAR is expected to be delivered from IBM in a release (if any)
  to be available within the next 24 months.
  
  The solution for this APAR is included in CS for z/OS Version 1
  Release 13.
  

APAR Information

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

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

Fix information

Applicable component levels

• R1A0 PSN

     UP

• R1B0 PSN

     UP

• R1C0 PSN

     UP