Ubuntu telnet設置
Linux系統，在很多企業中都有著巨大的作用。不少的管理員也希望Linux系統可以包含更多的功能。這里我們就來介紹一下Ubuntu telnet的相關設置與操作。
1. sudo apt-get install xinetd telnetd
2. Ubuntu telnet安裝成功后,系統也會有相應提示: 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并加入以下內容:
- # 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并加入以下內容:
- # 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. 重啟機器或重啟Ubuntu telnet網絡服務服務sudo /etc/init.d/xinetd restart
6. 使用TELNET客戶端遠程登錄即可進行非root用戶訪問.
7.使用root登錄: mv /etc/securetty /etc/securetty.bak 這樣root可以登錄了.也可這樣: 修改/etc/pam.d/login這個文件.只需將下面一行注釋掉即可. #auth required lib/security/pam_securetty.so
8. Ubuntu telnet詳細配制
- /etc/xinetd.d/telnet service telnet
- {
- disable =no bind =192.168.1.2 only_from=192.168.1.0/24 #上面這兩行說明僅提供內部網段!
- 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}
- #上面三行設置外部較為嚴格的限制 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.加設防火墻iptables: 如果想要針對192.168.0.0/24這個網段及61.xxx.xxx.xxx這個IP進行telnet開放,可以增加下面幾行規則: /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.加設防火墻/etc/hosts.allow(deny)機制: 上面開放了192.168.0.0/24這個網段,但是如果您只想讓其中的192.168.0.1~192.168.0.5進入,可以設置如下 : 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
