IJ04407: SMALL CHECKSUM OFFLOAD PACKETS SENT VIA SEA HAVE INVALID TCP SUMAPPLIES TO AIX 7100-05

APAR status

• Closed as program error.

Error description

• Small TCP packets sent via a SEA with checksum offload
  enabled will not have the proper TCP checksum on the
  receiving side.
  
  The coding error is in lncentdd, mlxentdd, mlxcentdd, and
  shientdd.  The only platform that will see the issue is
  the VIOS.  And the issue will only be seen if all of the
  IP and TCP options such as timestamps and sack are turned
  off.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:
  * Systems running the 7100-05 Technology Level with
  * any of the following filesets at or between the given levels:
  * MIN          MAX          FILESET
  * 7.1.5.0      7.1.5.15     devices.ethernet.lnc.rte
  * 7.1.5.0      7.1.5.15     devices.ethernet.lnc2.rte
  * 7.1.5.0      7.1.5.15     devices.ethernet.mlx.rte
  * 7.1.5.0      7.1.5.15     devices.ethernet.mlxc.rte
  * 7.1.5.0      7.1.5.15     devices.ethernet.shi.rte
  ****************************************************************
  * PROBLEM DESCRIPTION:
  * Small TCP packets sent via a SEA with checksum offload
  * enabled will not have the proper TCP checksum on the
  * receiving side.
  * The coding error is in lncentdd, mlxentdd, mlxcentdd, and
  * shientdd.  The only platform that will see the issue is
  * the VIOS.  And the issue will only be seen if all of the
  * IP and TCP options such as timestamps and sack are turned
  * off.
  ****************************************************************
  * RECOMMENDATION:
  * Install APAR IJ04407.
  ****************************************************************
  

Problem conclusion

• Fixed the code in network device driver to properly handle
  packets less than supported min packet size.
  

Temporary fix

Comments

• 6100-09 - use AIX APAR IJ03186
  6100-09 - use AIX APAR IJ03186
  6100-09 - use AIX APAR IJ03186
  7100-05 - use AIX APAR IJ04407
  7100-05 - use AIX APAR IJ04407
  7200-02 - use AIX APAR IJ06064
  

APAR Information

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

  IJ03186

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

  U882084

Fix information

• Fixed component name

  AIX V7.1

• Fixed component ID

  5765H4000

Applicable component levels

• R710 PSY U882084

     UP18/08/22 I 1000 Ø