PI29994: FTP CLIENT CONFIRGURED FOR PASSIVE CONNECTIONS WILL FALL BACK TO ACTIVE MODE WHEN EPSV AND PASV COMMANDS SENT TO SERVER FAIL

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The zOS FTP client attempted to establish a passive connection
  (pasv & epsv) with the remote server, but for some reason that
  server was not allowing passive connections. So by design the
  FTP client resorts to setting up an ACTIVE FTP session, which
  requires the client to listen on the same local port that it
  used in the control connection.
  
  Under normal circumstances this is not an issue, but in cases
  where TCP UNRSV port statements with SAF checks are defined.
  ICH408I servauth read voliations may occur because the zOS ftp
  client attempted to bind/listen on an unreserved port.
  
  
  
  
  
  
  
  
  Additional Symptom(s) Search Keyword(s): FTP client passive
  active mode
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications          *
  *                 Server for z/OS Version 1 Release 13:        *
  *                 FTP                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: In a passive mode connection,           *
  *                      when the remote server rejects          *
  *                      the client's connection request,        *
  *                      the client falls back to active         *
  *                      mode.                                   *
  ****************************************************************
  * RECOMMENDATION: Apply PTF.                                   *
  ****************************************************************
  
  +-------------------------------------------------------------+
  + 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

• FTP client has been updated to return when passive mode
  fails and passiveOnly parameter is set to TRUE. It will
  not try to start the data connection using active mode.
  
  * Cross Reference between External and Internal Names
  EZAFTPSM (FTPDMSG )
  

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:

  PI36683 UI26945

Modules/Macros

•    EZAFTPAC EZAFTPCL EZAFTPCY EZAFTPDM EZAFTPEH
  EZAFTPEJ EZAFTPEP EZAFTPGL EZAFTPGM EZAFTPMK EZAFTPM9 EZAFTPRM
  EZAFTPRX EZAFTPSC EZAFTPSM EZAFTPSR
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1D0 PSY UI26945

     UP15/06/24 P F506

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.