Troubleshooting radius is a crappy task. But crappy articles don’t help: http://support.apple.com/kb/HT3929 To be more specific, the debug mode flag is -X (not sure why that was so hard). In that case it’s doing single server mode and the process cannot fork. You can also do the lowercase, -x (which is part of -X), or -xx for further granularity. In order to set the launchd item to debug mode you would therefore find the /System/Library/LaunchDaemons/org.freeradius.radiusd.plist file (only created once you’ve fired up RADIUS btw). From here, locate the array for invoking the command: <string>/usr/sbin/radiusd</string> <string>-sf</string> Change the -sf to either a -X or add an x or two in there…