Ubuntu telnet设置

Linux系统，在很多企业中都有着巨大的作用。不少的管理员也希望Linux系统可以包含更多的功能。这里我们就来介绍一下Ubuntu telnet的相关设置与操作。

1. sudo apt-get install xinetd telnetd

2. Ubuntu telnet安装成功后,系统也会有相应提示: sudo vi /etc/inetd.conf并加入以下一行 telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd

3. sudo vi /etc/xinetd.conf并加入以下内容:

# 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

}

includedir /etc/xinetd.d

4. sudo vi /etc/xinetd.d/telnet并加入以下内容:

# 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

}

5. 重启机器或重启Ubuntu telnet网络服务服务sudo /etc/init.d/xinetd restart

6. 使用TELNET客户端远程登录即可进行非root用户访问.

7.使用root登录: mv /etc/securetty /etc/securetty.bak 这样root可以登录了.也可这样: 修改/etc/pam.d/login这个文件.只需将下面一行注释掉即可. #auth required lib/security/pam_securetty.so

8. Ubuntu telnet详细配制

/etc/xinetd.d/telnet service telnet

{

disable =no bind =192.168.1.2 only_from=192.168.1.0/24 #上面这两行说明仅提供内部网段!

Instance =UNLIMITED Nice =0 Flags =REUSE socket_type=stream wait =no user =root

#server =/usr/sbin/telnetd server =/usr/sbin/in.telnetd server_args =-a none log_on_failure +=USERID

} service telnet

{

disable =no bind =140.116.142.196 only_from=140.116.0.0/16 no_access=140.116.32.{10,26}

#上面三行设置外部较为严格的限制 instance =10 umask =022 nice =10 flags =REUSE socket_type=stream wait =no user =root

#server =/usr/sbin/telnetd server =/usr/sbin/in.telnetd log_on_failure +=USERID

}

9.加设防火墙iptables: 如果想要针对192.168.0.0/24这个网段及61.xxx.xxx.xxx这个IP进行telnet开放,可以增加下面几行规则: /sbin/iptables -A INPUT -p tcp -i eth0 -s 192.168.0.0/24 --dport 23 -j ACCEPT /sbin/iptables -A INPUT -p tcp -i eth0 -s 61.xxx.xxx.xxx --dport 23 -j ACCEPT /sbin/iptables -A INPUT -p tcp -i eth0 --dport 23 -j DROP

10.加设防火墙/etc/hosts.allow(deny)机制: 上面开放了192.168.0.0/24这个网段,但是如果您只想让其中的192.168.0.1~192.168.0.5进入,可以设置如下 : vi /etc/hosts.allow in.telnetd:192.168.0.1,192.168.0.2,192.168.0.3,192.168.0.4,192.168.0.5:allow