01. Login to your server through SSH as a root user.
02. Open file
03. Look for the line: disable = no and replace with disable = yes
04. Now restart the inetd service:
05. Make sure it is turned through chkconfig as well because it can still start through that.
[root@daddylinux~]#/sbin/chkconfig telnet off
06. Scan your server to ensure port 23 is closed.
[root@daddylinux~]#nmap -sT -O localhost
Also run ps -aux | grep telnet and if you find anything other than “grep telnet” as result kill the process.