Linux裡面配置ADSL上網是件很麻煩的事。但配置完成之後就能開機自動撥號上網，可謂十分的方便。支持的系統有Redhat,CentOS,SuSE,FreeBSD,Ubuntu等常見的Linux。
工具/原料 ADSL網絡，電信，網通，移動等常見寬帶。
Linux系統的安裝光盤，可以到各鏡像站點下載到
方法/步驟 安裝系統。可以選擇圖形化安裝界面，或者文本安裝界面。對於新手和對安全性比較高的用戶來說，最好選擇圖形化安裝界面，因為安裝十分的簡單。
到終端裡進行配置。在終端裡輸入adsl-setup
[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
basic. You are strongly encouraged to use a more sophisticated firewall
setup; however, these will provide basic security. If you are
running any servers on your machine, you must choose ‘NONE’ and set up
firewalling yourself. Otherwise, the firewall rules will deny access
to all standard servers like Web, e-mail, ftp, etc. If you are
using SSH, the rules will block outgoing SSH connections which allocate
a privileged source port. ’選擇防火牆的等級，0到2，按需要選。
The firewall choices are: 0 -
NONE: This script will not set any firewall rules. You are responsible for
ensuring the security of your machine. You are STRONGLY recommended
to use some kind of firewall rules. 1 -
STANDALONE: Appropriate for a basic stand-alone web-surfing
workstation 2 -
MASQUERADE: Appropriate for a machine acting as an Internet gateway
for a LAN
Choose a type of firewall (0-2): 0
Start this connection at boot time
Do you want to start this connection at boot time? ‘是否在啟動時自動連接？
Please enter no or yes (default no):y
**
Summary of what you entered ** ’以下是ADSL賬號設置信息
Ethernet
Interface: eth0
User name: nj007.cn
Activate-on-demand: No
DNS addresses: Supplied by ISP’s server
Firewalling: NONE
User Control: y
Accept these settings and adjust configuration files (y/n)? y ‘以上信息正確嗎，Y保存，N重填。
Adjusting
/etc/sysconfig/network-scripts/ifcfg-ppp0
Adjusting
/etc/ppp/chap-secrets and /etc/ppp/pap-secrets
(But first backing it up to /etc/ppp/chap-secrets.bak)
(But first backing it up to /etc/ppp/pap-secrets.bak)
Congratulations, it should be all set up!
Type ‘/sbin/ifup ppp0′ to bring up your xDSL link and ‘/sbin/ifdown ppp0′
to bring it down.
Type ‘/sbin/adsl-status /etc/sysconfig/network-scripts/ifcfg-ppp0′ to see
the link status.
已經完成配置ADSL寬帶連接，接下來，重啟LINUX即可。命令reboot或者shutdown -r now
登錄到linux，使用ping命令，ping一些常用網站如baidu.com，如果返回結果有響應時間則連接成功，反之則檢查以上步驟。
