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

Fixes are available

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

Tips

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

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R700 PSY

Document Information

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