How to Disable Telnet

1. SSH into server and login as root.
2. At shell command prompt type the following command and press Enter. This example use pico to edit text file, you can use vi or other text editor if you want.

pico -w /etc/xinetd.d/telnet

3. Locate the following line:

disable = no

Change the “disable = no” to “disable = yes” (no to yes).

4. Save and exit.
5. Restart the inetd service by using the following command:

/etc/rc.d/init.d/xinetd restart

6. Turn off Telnet through chkconfig as well because it can still start through that:

/sbin/chkconfig telnet off

Fedora Linux user the following command:
# yum install telnet-server telnet

Red Hat enterprise Linux user type the following command:
up2date telnet-server telnet

FreeBSD user type the following command:
No need to install new (telnet server) package, it is installed by default (/usr/libexec/telnetd)