Linux下设置ADSL自动拨号上网

  前段时间下载了红帽的linux，版本为redhat 9.0，整整刻了三张CD。最初是为了体验一下linux下QQ聊天软件的功能，最后因内核太低（官方推荐内核在2.6以上，我下载的版本是2.4）而告终。最大的收获是了解了linux下文件系统及linux下软件与windows的不同，还有linux下ADSL的连接设置。
 linux下局域网的连接很简单，在菜单的网络设置里，填好IP地址及子网掩码就OK了，ADSL的连接要费些周折了。前面的博文里介绍了如何设置windows下不用路由自动拨号上网的技巧，linux下也有相同点，就是要一步一步的输入上网信息，建立连接。不同点就是在linux要通过输入指令来完成ADSL的设置。

首先打开终端，在终端里输入adsl-setup ,根据提示，完成设置：

[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)  ‘此处输入ADSL的用户名。
　　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):  ‘直接用默认的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): ‘输默认的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，南京地区的主DNS为218.2.135.1，辅DNS为61.147.37.1其它地区可参照

当地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 ‘输入ADSL密码，默认为自己的电话号码
　　Please enter your Password:   ’再次输入密码
　　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  ‘是否允许普通用户开启或关闭ADSL连接，默认允许。
FIREWALLING
Please choose the firewall rules to use. Note that these rules are very