Preventing Duplicate IP Addresses when Cloning RS/6000 SP Nodes


About this document
    Related documentation
Why duplication occurs

About this document

This document details the steps needed to prevent the duplication of IP addresses on nodes when cloning RS/6000 SP nodes within the same complex.

This procedure applies to:

Related documentation

The product documentation library is available: .html

Why duplication occurs

During the restoration of a mksysb on a RS/6000 SP node, at one time, the node will have the same IP address as the node that the mksysb was created from. After NIM completes the restoration of the mksysb image and executes the pssp_script , the node will reboot. After the node reboots, it creates all of the adapters and assigns any IP addresses that are found in the /tmp/bos/objrepos.inst/CuAt.sav file. The machine that executes the mksysb creates the file from its ODM. PSSP puts a line in the /etc/inittab file that executes the /usr/lpp/ssp/install/bin/psspfb_script. This script removes the IP addresses from all adapters and reassigns the IP addresses that are in the SDR for this node. Therefore, until this script completes successfully, there are two nodes with the same IP address. Take note, however, that you will only notice this problem if you actually try to access the IP address that is duplicated.


The entries for the adapters in the /tmp/bos/objrepos.inst/CuAt.sav file must be removed. The following procedure accomplishes this task:

  1. Move the script.cust file on the control workstation to the /tftpboot directory, enter:
       /usr/bin/mv /usr/lpp/ssp/samples/script.cust /tftpboot/script.cust

  2. Using your preferred editor, open the /tftpboot/script.cust file and add the following lines to the bottom of the script.
  3.    /usr/bin/grep -vp en0 /tmp/bos/objrepos.inst/CuAt.sav| \
       /usr/bin/grep -vp en1 | /usr/bin/grep -vp tr0| \
       /usr/bin/grep -vp inet0 > /tmp/bos/objrepos.inst/CuAt.sav2
       /usr/bin/cp /tmp/bos/objrepos.inst/CuAt.sav /tmp/bos/objrepos.inst/CuAt.old
       /usr/bin/cp /tmp/bos/objrepos.inst/CuAt.sav2

Now whenever a node is installed, the /tftpboot/script.cust file will be transferred from the control workstation to the node and executed before NIM will reboot the node.

NOTE: Any adapter can be added to the script by adding the following:

    |/usr/bin/grep -vp <adapter#>
before the ">" in the third line.  "\" is a line continuation character, so the first three lines are all part of the same command.

For more information on the script.cust file and how it can be used, see "Appendix C, User-Supplied Node Customization Scripts," in Parallel System Support Programs for AIX Installation and Migration Guide.

[ Doc Ref: 97000792410094     Publish Date: Nov. 10, 2000     4FAX Ref: 8720 ]