Basic Telnet operation in Linux

Yum Install telnet*-y install Telnet

Vim/etc/xinetd.d/telnet Modifying a configuration file

# Default:on
# description:the Telnet Server serves Telnet sessions; It uses \
# unencrypted Username/password pairs for authentication.
Service Telnet
{
Flags = Reuse#socket REUSABLE

Socket_type = stream# Connection mode is TCP

Wait = no# starts a process for each request

user = root# to start the service as root

Server =/usr/sbin/in.telnetd# The process to be activated

Log_on_failure + = userid# logged in User name when login fails

Disable = no# enabled

Instance = 3
}
Configure the clients that are allowed to log on, join
Only_from = 192.168.0.2 #只允许192.168.0.2 Login
Configure the list of clients that are forbidden to log on, join
No_access = 192.168.0. {2,3,4} #禁止192.168.0.2, 192.168.0.3, 192.168.0.4 Login
Set open hours, join
Access_times = 9:00-12:00 13:00-17:00 # Only these two hours per day open service (Our office Hours: P)
Configure the IP address of the binding private network such as 192.168.0.2, then join
bind = 192.168.0.2
Specific configuration can refer to Xined profile property description (man xinetd.conf)

/ETC/INIT.D/XINETD Restart Restart Service
Service xinetd Restart Restart services

In general, Telnet does not allow root login primarily for security reasons, you can log in with a regular account before using Su-cut to root user

Vim/etc/services to modify the remote login port for this host

Telnet 23/tcp
Telnet 23/UDP

Basic Telnet operation in Linux