HP -UX B6941-90001 Administrator's Reference Manual page 59

Problems with IP Aliases in AIX OS
One very important consequence of setting the IP alias on the interface
is that HACMP no longer works correctly. This is true for all events that
deal with IP addresses, such as; acquire service address, acquire
takeover address, swap adapter, and so on. The problem is due to a
flaw in the AIX OS, and may be addressed in the following way:
• download and install the appropriate fix(es) for the AIX OS
For managed nodes where AIX OS fixes have already been installed,
refer to "Pre-Installation Instructions for Managed Nodes with the AIX
OS Patch for IP Aliases" on page 59.
It is highly recommended that the appropriate fixes for the AIX OS are
installed to overcome the problems with IP aliases and HACMP. The
fixes may be obtained using IBM's FixDist package or from their web
site. The following APARs can be used to obtain the fixed versions of
related packages:
• AIX 4.2 IX75987
• AIX 4.3 IX78397
Only after the fixes for the AIX OS have been installed will HACMP
function properly: some HACMP functionality does not work on managed
nodes without the AIX OS fixes installed (e.g. swap adapter event).
Pre-Installation Instructions for Managed Nodes with
the AIX OS Patch for IP Aliases
All HACMP events work once the AIX OS fixes are installed and the IP
alias is set on the interface. However, due to a minor problem with the IP
alias address itself, you do have to reset the IP alias on the interface
after each change of the IP address - the IP alias address no longer works
after the ifconfig command is used to change the main IP address on
the interface. Note that you have to reset the IP alias on all cluster nodes
where the ITO agent is to be installed. The following shell script may be
used to set the IP alias on the interface where the service or boot IP
address is set:
#!/bin/sh
ALIAS_IP="192.168.1.54"
SERVICE_IP=`/usr/sbin/cluster/utilities/cllsif -cSi \
$LOCALNODENAME | grep ":service:.*:ether" | cut -d: -f7 | uniq`
BOOT_IP=`/usr/sbin/cluster/utilities/cllsif -cSi $LOCALNODENAME |\
grep ":boot:.*:ether" | cut -d: -f7 | uniq`
INTERFACE=`/usr/sbin/cluster/utilities/clgetif -a $SERVICE_IP`
Chapter 2
Installing ITO Agents on the Managed Nodes
General Installation Tips for Managed Nodes
59