How to install & turn on telnet service on RHEL, Fedora, CentOS, Ubuntu, FreeBSD, Debian

Last Updated on Sunday, 02 September 2012 07:35 Written by Rudy Saturday, 01 September 2012 10:04

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TELNET (TELetype NETwork) is a network protocol used on the Internet or local area network LAN connections.

 

The telnetd program (telnet server) is a server which supports the DARPA telnet interactive communication protocol. Telnetd is normally invoked by the internet server inetd or xinetd for requests to connect to the telnet port as indicated by the /etc/services file. Usaually telnet listen on port TCP port 23.

Telnet in is insecure protocol and it is recommended that you use ssh server. But some time you really need telnet then first install telnet server as according to version of Linux distribution.

Telnet server installation

WARNING! Installing telnet open your computer to unencrypted network communication, which is a bad idea. If possible avoid telnet; and use secure shell called ssh.

Debain/Ubuntu Linux user type the following command:

# apt-get install telnetd

OR

$ sudo apt-get install telnetd

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)

Configure telnet server (turn on telnet server)

Again each distribution has its own method to turn on or off telnet service; same applies to telnet UNIX/Linux server.

If you are using Red Hat / Fedora Linux
The configuration file for telnet is /etc/xinetd.d/telnet. To enable telnet server you need to open this file and make sure disable = no read as disable = yes.
Alternately,

# chkconfig telnet on

To start telnet server type command:

# /etc/init.d/xinetd restart

If you are using Debian Linux
The configuration file for telnet is /etc/inetd.conf. By default it is enabled when you install telnet server. To start telnet server type command:

# /etc/init.d/inetd restart

If you are using FreeBSD
The configuration file for telnet is /etc/inetd.conf. Open file using vi text editor and uncomment line:

# vi /etc/inetd.conf

Make sure commented line:

#telnet stream tcp nowait root /usr/libexec/telnetd telnetd

Read as follows:

telnet stream tcp nowait root /usr/libexec/telnetd telnetd

Save and close the file. Start telnet service:

Enable inetd service so that telnet get loaded:

# vi /etc/rc.conf

Append/add following line to configuration file:

inetd_enable=”YES”

Save and close the file, Rsstart telnet via inetd service:

# /etc/rc.d/inetd restart

Telnet to server (How do I use telnet client?)

You should now be able to telnet to the server from Windows or Linux desktop system. Type the following command to connect to Telnet server:

telnet server-ip-address
telnet 192.168.1.5

The configuration file for telnet is /etc/inetd.conf. By default it is enabled when you install telnet server. To start telnet server type command:You should now be able to telnet to the server from Windows or Linux desktop system. Type the following command to connect to Telnet server