I am, alas, not overly familiar with HP-UX, but one option you might want to try is to run the Linux NIS code on HP-UX. If you can, use a test system, or at worst a test area on some system you have, but the Linux code is pretty generic as Unix code goes and ports pretty easily.
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.