Checklist!!! How very 1090's of you.
AIX has the built-in command aixpert that applies 100's of system hardening rule for you.
These have been created by the the IBM Security team. There is typically, improved rules with each AIX version - so update AIX to get the latest set.
There are different profiles that you can apply for your industry.
You can disable rules you don't like for example default is NFS is blocked but if you use that you can switch off the NFS rule.
For a quick at my YouTube video for a quick start: https://youtu.be/L1MmuZOntxI?si=vhyZSDC1zHdav-BS
If you have 100's of AIX's running you can use PowerSC (it costs money) to automatically apply the rules to lots of servers and check they are still applied (no sysadmin fiddling with the setting).
I hope this helps.
ps: the Video has been available since 2008 - How come you have not found it before now? :-)
You could do worse than to check my other videos on Power hardware, AIX features and nmon/njmon.
At https://www.youtube.com/@nigelargriffiths
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Nigel Griffiths - IBM retired
London, UK
@mr_nmon
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