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PM89272: LIBERTY PROFILE SERVER OPENS EXTRA LISTENER ON EPHEMERAL PORT AND LOCALHOST

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Netstat shows the Liberty Server has opened up a listener that
    is not defined.  It is bound to an ephemeral port and localhost
    
    An example of this is
    SVR1  00007B46 Listen
      Local Socket:   ::ffff:127.0.0.1..1547
      Foreign Socket: ::ffff:0.0.0.0..0
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  All users of IBM WebSphere Application      *
    *                  Server Liberty Profile                      *
    ****************************************************************
    * PROBLEM DESCRIPTION: WebSphere Application Server Liberty    *
    *                      Profile servers open up an ephemeral    *
    *                      port, which may be undesirable,         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    WebSphere Application Server Liberty Profile servers open up
    an ephemeral command port for the purposes of communication
    with the server script.  The ephemeral port is necessary in
    order for the server script to perform certain functions
    against a running server, such as stopping the server or
    requesting a Java dump.
    The opening of ephemeral ports can be surprising, particulary
    for users who run frequent port scans on their system and are
    continually surprised to find open ports that they were
    unaware of.
    

Problem conclusion

  • The command port is unnecessary for WebSphere Application
    Server for z/OS Liberty Profile servers that are started as a
    started task, because z/OS operator console commands can be
    used to perform most tasks that the server script can
    perform.  In this environment, the command port has been
    disabled by default, and new z/OS operator console commands
    were added so that all function provided by the server script
    is now also provided by z/OS operator console commands.
    
    In all other environments, the server will still open an
    ephemeral command port by default.  However, a new bootstrap
    property "command.port" has been provided that can be used to
    specify a specific port number to use for the command port.
    
    The fix for this APAR is currently targeted for inclusion in
    fix pack 8.5.5.2. Please refer to the Recommended Updates page
    for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM89272

  • Reported component name

    LIBERTY - Z/OS

  • Reported component ID

    5655W6514

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2013-05-17

  • Closed date

    2013-08-27

  • Last modified date

    2013-10-02

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

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

Fix information

  • Fixed component name

    LIBERTY - Z/OS

  • Fixed component ID

    5655W6514

Applicable component levels

  • R850 PSY

       UP



Document information

More support for: WebSphere Application Server for z/OS

Software version: 850

Reference #: PM89272

Modified date: 02 October 2013


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