>I'm in the process of intalling Secure Shell Package. To boost security
>of our cluster, I plan to disable telnetd, rlogind and maybe ftpd.

To disable most internet services, you have to edit the /etc/inetd.conf file. You should, after installing ssh, disable everysingle line in that file except the ftpd if your hardcore about setting up a secure server/workstation.

Send a HUP signal to the inetd process afterwards.

As far as configuring ftpd to only accept anonymous, create a file called /etc/ftpusers with a list of every single entry in your /etc/passwd file, except the anonymous user. This will disallow any user from ftp'ing into the box except 'anonymous'.

—Basit