Surprisingly, the best tool for troubleshooting NetScaler authentication process in not a log file, located somewhere in the depths of log directory. Instead, they have a named pipe “aaad.debug” in the
/tmp directory. This is not a regular file, so you cannot download it or open in the editor. The correct way to work with named pipe will be to
cat its “content” – either directly to the console or to some file.
root@...# cd /tmp root@...# cat aaad.debug
The following great (and simple!) article in the Citrix KB explains it in-depth: “How to Troubleshoot Authentication with Aaad.debug”.