IBM Support

PH30839: LB DOESN'T DETECT NETMASK 255.255.255.128 AND HIGHER

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APAR status

  • Closed as program error.

Error description

  • When LB is deployed on a small subnet, forwarding may not work
    as expected because LB does not detect netmask of
    255.255.255.128 and higher on AIX.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  IBM WebSphere Application Server Load       *
    *                  Balancer for IPv4 and IPv6 users on AIX     *
    ****************************************************************
    * PROBLEM DESCRIPTION: Load balancer does not                  *
    *                      recognize local subnet mask higher      *
    *                      than 255.255.255.128 (prefix 26)        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When the executor is started, Load Balancer determines local
    interface information such as network mask. If the local
    subnet mask is greater than 255.255.255.128 (prefix 26), the
    load balancer will use mask 255.255.255.128 (prefix 26)
    instead of the actual mask. This can affect packet forwarding
    and give false errors that servers are not on the same subnet
    as the load balancer.
    

Problem conclusion

  • Corrected the code to calculate the mask accurately.
    
    Fix levels:
       8.5.5.19
       9.0.5.7
    

Temporary fix

Comments

APAR Information

  • APAR number

    PH30839

  • Reported component name

    WS EDGE LB IPV4

  • Reported component ID

    5724H8812

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-10-26

  • Closed date

    2020-10-28

  • Last modified date

    2020-10-28

  • 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

    WS EDGE LB IPV4

  • Fixed component ID

    5724H8812

Applicable component levels

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU029","label":"Software"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.5"}]

Document Information

Modified date:
29 October 2020