IBM Support

PI26507: mod_proxy on z/OS doesn't try IPV4 addresses on systems where IPV6 connections fail

Fixes are available

8.5.5.4: WebSphere Application Server V8.5.5 Fix Pack 4
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
8.5.5.5: WebSphere Application Server V8.5.5 Fix Pack 5
8.5.5.6: WebSphere Application Server V8.5.5 Fix Pack 6
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • mod_proxy will report attempts to connect to IPv6 addresses
    such as "attempt to connect to [1080::8:800:200C:417A]:80
    failed", but if IPv4 addresses are also available for this
    host they will not be tried.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Users of IBM HTTP Server with mod_proxy on  *
    *                  IPv6 enabled z/OS systems.                  *
    ****************************************************************
    * PROBLEM DESCRIPTION: If an origin server has both            *
    *                      IPv4 and IPv6 addresses, mod_proxy      *
    *                      may not try the IPv4 addresses.         *
    ****************************************************************
    * RECOMMENDATION:  Apply this fix if mod_proxy is failing      *
    *                  to connect to IPv6 addresses and logs       *
    *                  do not show the IPv4 address being tried.   *
    ****************************************************************
    On z/OS the POSIX call getaddrinfo() differs from other
    implemnentations in a way that prevents mod_proxy from seeing
    both IPv6 and IPv4 addresses for a given hostname.  In the
    event that the returned IPv6 addresses are not reachable,
    mod_proxy cannot try IPv4 addresses.
    

Problem conclusion

  • The Apache Portable Runtime was updated to always pass the
    "AI_ALL" hint when asking for addresses from family AF_UNSPEC
    on z/OS.
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI26507

  • Reported component name

    WAS IHS ZOS

  • Reported component ID

    5655I3510

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2014-09-26

  • Closed date

    2014-09-30

  • Last modified date

    2015-03-10

  • 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

    WAS IHS ZOS

  • Fixed component ID

    5655I3510

Applicable component levels

  • R700 PSY

       UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
28 April 2022