前段時間下載了紅帽的linux，版本為redhat 9.0，整整刻了三張CD。最初是為了體驗一下linux下QQ聊天軟件的功能，最后因內核太低（官方推薦內核在2.6以上，我下載的版本是2.4）而告終。最大的收獲是了解了linux下文件系統及linux下軟件與windows的不同，還有linux下ADSL的連接設置。
 linux下局域網的連接很簡單，在菜單的網絡設置里，填好IP地址及子網掩碼就OK了，ADSL的連接要費些周折了。前面的博文里介紹了如何設置windows下不用路由自動撥號上網的技巧，linux下也有相同點，就是要一步一步的輸入上網信息，建立連接。不同點就是在linux要通過輸入指令來完成ADSL的設置。

首先打開終端，在終端里輸入adsl-setup ,根據提示，完成設置：

[root@localhost root]# adsl-setup
Welcome to the ADSL client setup. First, I will run some checks on
system to make sure the PPPoE client is installed properly…
LOGIN NAME
Enter  your Login Name (default root): (username)  ‘此處輸入ADSL的用戶名。
　　INTERFACE
Enter the Ethernet interface connected to the ADSL modem For
Solaris, this is likely to be something like /dev/hme0. For
Linux, it will be ethX, where ‘X’ is a number. (default eth0):  ‘直接用默認的eth0就行了。
　　Do you want the link to come up on demand, or stay up continuously?
If you want it to come up on demand, enter the idle time in seconds
after which the link should be dropped. If you want the link to stay up
permanently, enter ‘no’ (two letters, lower-case.)
NOTE:
Demand-activated links do not interact well with dynamic IP addresses.
You may have some problems with demand-activated links.
Enter the demand value (default no): ‘輸默認的NO
　　DNS
Please enter the IP address of your ISP’s primary DNS server.
If your ISP claims that ‘the server will provide dynamic DNS addresses’,
enter
‘server’ (all lower-case) here. ’DNS地址，南京地區的主DNS為218.2.135.1，輔DNS為61.147.37.1其它地區可參照

當地ISP
　　If you just press enter, I will assume you know what you are doing
and not modify your DNS setup.
Enter
the DNS information here: server
PASSWORD ‘輸入ADSL密碼，默認為自己的電話號碼
　　Please enter your Password:   ’再次輸入密碼
　　Please re-enter your Password:
USERCTRL
Please enter ‘yes’ (two letters, lower-case.) if you want to allow normal
user to start or stop DSL connection (default yes): y  ‘是否允許普通用戶開啟或關閉ADSL連接，默認允許。
FIREWALLING
Please choose the firewall rules to use. Note that these rules are very