RHELServer5.5telnet installation and configuration

Summary of RHELServer5.5telnet installation and configuration: 1. install telnet and telnet-server2 correctly. modify the telnet configuration and restart the xinetd service. modify the iptables firewall and open port 231. first check whether telnet is installed with the [root@www.linuxidc.com/] rpm-qa | greptelnettelnet-0.17-39.e1

RHEL Server 5.5 telnet installation and configuration highlights:

1. Correctly install telnet and telnet-server

2. Modify the telnet configuration and restart the xinetd service.

3. Modify the iptables firewall and open port 23.

1. Check whether telnet is installed.

[Root @ www.linuxidc.com/] rpm-qa | grep telnet

Telnet-0.17-39.e15

Telnet-server-0.17-39.e15

To successfully enable the telnet service, you must have the telnet-server suite. If not, install it.

2. Modify the telnet configuration and save it.

[Root @ www.linuxidc.com/] vim/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 % enable telent. yes indicates disable telnet.
}

Restart the xinetd service

[Root @ www.linuxidc.com/] service xinetd restart

Telnet to the server: the linux address in my VM is 10.121.122.34.

The system prompts that the login failed because the connection to port 23 failed.

3. Modify the iptables Firewall Configuration:

[Root @ www.linuxidc.com/] vim/etc/sysconfig/iptables
Add the following content:
-A RH-Firewall-1-INPUT-m state -- state NEW-m tcp-p tcp -- dport 23-j ACCEPT

Restart the iptables service:

[Root @ www.linuxidc.com/] service iptables restart

Telnet again: Access is successful now.

PS: by default, the root user cannot log on via telnet. it is unwise to enable telnet to the root user.

Because we can use sudo to switch the root identity, there is no need to take this risk.