Install and Enable Telnet server in Ubuntu Linux

转：http://ubuntuguide.net/install-and-enable-telnet-server-in-ubuntu-linux

参考：http://auxnet.org/index.php?option=com_content&view=article&id=62:how-to-install-a-turn-on-telnet-service-on-rhel-fedora-centos-ubuntu-freebsd-debian&catid=1:latest-news&Itemid=50

 本方法也适用于Debian Linux。

Install and Enable Telnet server in Ubuntu Linux

1.Install telnet use this command in terminal(Applications/Accessories/Terminal):

sudo apt-get install xinetd telnetd 

2.Edit /etc/inetd.conf using your favourite file editor with root permission,add this line:

telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd

注意：如果inetd.conf不存在，可以手动创建

3.Edit /etc/xinetd.conf,make its content look like following:

# Simple configuration file for xinetd
#
# Some defaults, and include /etc/xinetd.d/
defaults

{

# Please note that you need a log_type line to be able to use log_on_success

# and log_on_failure. The default is the following :

# log_type = SYSLOG daemon info

instances = 60

log_type = SYSLOG authpriv

log_on_success = HOST PID

log_on_failure = HOST

cps = 25 30

}

4.You can change telnet port number by edit /etc/services with this line:

telnet        23/tcp 

5.If you’re not satisfied with default configuration.Edit etc/xinetd.d/telnet, add following:

# default: on
# description: The telnet server serves telnet sessions; it uses
# unencrypted username/password pairs for authentication.
service telnet

{

disable = no

flags = REUSE

socket_type = stream

wait = no

user = root

server = /usr/sbin/in.telnetd

log_on_failure += USERID

}

add these lines as you like:（以下内容可以不添加）

only_from = 192.168.120.0/24 #Only users in 192.168.120.0 can access to
only_from = .bob.com #allow access from bob.com
no_access = 192.168.120.{101,105} #not allow access from the two IP.
access_times = 8:00-9:00 20:00-21:00 #allow access in the two times
......

6.Use this command to start telnet server:

sudo /etc/init.d/xinetd restart