Hallo Kai,
es gibt auch noch ein Tool von der IBM:
CONTROLLING FTP SECURITY WITH EXIT PROGRAMS -- PART 2
Boy, just when I think I've published the definitive list of FTP exit
program resources, a helpful reader reminds me of another. The tool I
omitted is the free Secured TCP Utility (SECTCP), which was written by
IBMer Giovanni Perotti and is available at
http://www-922.ibm.com/easy400p/downloads.html*. The utility enables
you to secure FTP, WSG, and TELNET servers, log FTP, WSG, and TELNET
activity, and display HTTP, FTP, WSG, and TELNET daily logs. Another
downloadable utility, WSECTCP, provides a Web browser front-end to
SECTCP. Both utilities require OS/400 V4R4 or greater.

Thanks to Luis Rodrguez for the above tip.