If your flavor of Unix is running the inet daemon, you can disable telnet, ftp, rlogin, and so on by accessing the /etc/rc.conf file and setting the inetd_enable value to no:

inetd_enable=no

You can disable individual services by accessing the inetd.conf file and setting the associated line to no, or commenting the line out, as shown in Darwin and BSD environments such as OpenBSD or FreeBSD:

#telnet stream tcp  nowait  root  /usr/libexe/tcpd    telnetd

-- SP

48.9. The Linux proc Filesystem		48.11. Disallow rlogin and rsh