A: Adam Bishop - version - radiusd: FreeRADIUS Version 2.2.0 - while I think that later versions are always a good thing. I don't think the FreeRadius version is the culprit. Thanks for the pointer on debugging with GDB. A: Stefan Paetow - SElinux is off, thanks for su --shell=/bin/bash -l radiusd otptest (!!). A: Alan DeKok - I get it. Don't bother, go find another otp, I am not a serious programmer. Well, I already use multiple other otp's and write code in multiple languages for multiple platforms. So if someone can recommend an otpd package that is GPLv2, supports any OATH compliant token and will work with FreeRadius after rlm_otp is removed, I am interested. Meanwhile, I've written enough C to fix otpd several times in the past and probably won't give up just yet. Or to put it the question another way, what otp package are you recommending for use with FreeRadius? Thanks to all for the rapid and detailed responses. I have some work to do. PS: I used the phrase "mess with" as a colloqialism for "seriously applied proper programming and maintenance techniques to adjust the package to compile, link, make and install without error or warning under Fedora". Now back to fixing my first LINUX segfault. Cheers! /Mike