You do not want to run 8.1.0.1.  Period.  8.1.0.1 was first release and cureent patch level for 8.1 is 8.1.1.5 (some pople reported some issues which are not yet clear as to what exactly they apply so you may wish to use 8.1.1.4).

Next, do lslpp -L all | grep -i lgto*  and see what is reported.  I assume you did uninstall previous package.  If not, do installp -u LGTOnw.clnt.rte LGTOnw.man.rte and remove it.  Do lslpp check again.  Install should work fine - I run couple of AIX 7.1 boxes and never had an issue.  Note that early NW8 code did have issue with AIX installation so this is another reason to try one of recent patched versions.

I just tried another nsr 7.6.5.7 on another AIX 6.1 lpar and this was successfull. So I am sure that the networker package is not corrupted and that the problem is at the AIX level.

Thanks Hrvoje,

This is on a new, just created lpar. So no previous networker installation on it. I tried also with other levels of networker like 7.6.5.7 and 7.6.3.2 and had each time the same error. I don't think this is due to Networker but rather to a wrong AIX parameter.

I just downloaded networker 8.1.1 and the installation worked well. So there is an undocumented incompatibility betwen AIX 7.1 TL3 and nsr versions prior to 8.1.1

Thanks for your help.