在Windows系统中，telnet的配置相对简单一些。那么在Ubuntu Linux中的telnet的设置就相对比较麻烦了。不少朋友都对这个安装过程不熟悉。没有关系，这里我们就来对Ubuntu Linux telnet的安装设置进行一下讲解。
1. sudo apt-get install xinetd telnetd
2. Ubuntu Linux telnet安装后,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并加入以下内容进行下一步的Ubuntu Linux telnet设置:
- # 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. 重启机器或重启网络服务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 Linux telnet的详细配制/etc/xinetd.d/telnet#p#
- 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.Ubuntu Linux telnet最后一项设置，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
