Ubuntu 18.04
Install the packages
$ sudo apt-get update $ sudo apt install xinetd telnetd telnet -y Create a new file /etc/xinetd.d/telnet with following entries:
service telnet { disable = no flags = REUSE socket_type = stream wait = no user = root server = /usr/sbin/in.telnetd log_on_failure += USERID } Then restart xinetd service
$ sudo /etc/init.d/xinetd restart Time to test from server side:
$ telnet localhost CentOS-7
Install the packages
$ sudo yum clean all && yum repolist $ sudo yum install xinetd telnet-server telnet -y Enable and start the services
$ sudo systemctl enable telnet.socket $ sudo systemctl start telnet.socket Allow telnet (TCP/23) through the firewall
$ sudo firewall-cmd --permanent --add-port=23/tcp $ sudo firewall-cmd --reload Test from server side
$ telnet localhost