Failed to telnet to Red Hat Linux on the VM-Solution

The error is as follows:

Telent 192.168.141.123
Connecting to 192.168.141.123... the connection to the host cannot be opened. port 23: Connection Failed

Cause of failure:
1. Telnet package Not Installed
Check whether the Telnet package is installed
[Root @ localhost root] # rpm-Qa Telnet
Telnet-0.17-25
Indicates that you have installed

2. The Telnet package is installed, but the telnet server is not installed.
Check whether the telnet server is installed
[Root @ localhost root] # rpm-Qa telnet-Server
Telnet-server-0.17-25
Indicates that you have installed

If the telnet server is not installed, install the following::
1) load the third image disc of the system
2) mount Mount/dev/CDROM/mnt/CDROM
3) Find the telnet-server-0.17-25.i386.rpm (CD/mnt/CDROM/RedHat/RPMS)
4) install the RPM package
[Root @ localhost RPMs] # rpm-IVH telnet-server-0.17-25.i386.rpm
Warning: telnet-server-0.17-25.i386.rpm: V3 DSA Signature: nokey, key ID db42a60e
Preparing... ######################################## ### [100%]
1: telnet-server ##################################### ###### [100%]
[Root @ localhost RPMs] # rpm-Qa telnet-Server
Telnet-server-0.17-25

 

3. The Disable In the Telnet file is yes.
Change the value of disable to no or comment to change the line, and restart the xinetd daemon (Service xinetd restart)
[Root @ localhost root] # Cat/etc/xinetd. d/telnet
# Default: On
# Description: the telnet server serves Telnet sessions; it uses \
# Unencrypted username/password pairs for authentication.
Service telnet
{
Flags = Reuse
Socket_type = stream
Wait = No
User = root
Server =/usr/sbin/in. telnetd
Log_on_failure + = userid
Disable = No
}

The telnet file is available only after the telnet server is installed.

4. Firewall reasons: Linux Local Firewall
If the firewall is disabled, you do not need to add the row in the/etc/sysconfig/iptables file:-A RH-Firewall-1-INPUT-M state -- state new-m tcp-p tcp -- dport 23-J accept

Disable Firewall
Service iptables stop
It will expire after restart
To restart or disable the Firewall
Service iptables stop
Chkconfig iptables off

Note:
1. Firewall Configuration File:/etc/sysconfig/iptables
2. Start the Firewall Service: Service iptables start
3. Restart the Firewall Service: Service iptables restart
4. Disable the Firewall Service: Service iptables stop
5. By default, the root user cannot be used for telnet.
Solution 1: Modify the/etc/PAM. d/login file and comment out the auth required pam_securetty.so line.
Solution 2: log on with a common user and then switch to the root user