CentOS采用PPPOE拨号上网

yum install rp-pppoe -y

 pppoe-setup

[root@192 ~]# pppoe-setup
Welcome to the PPPoE client setup.  First, I will run some checks on
your system to make sure the PPPoE client is installed properly...


LOGIN NAME

Enter your Login Name (default root): 
#输入ISP提供的账户（上网帐号，这个是联通公司给我的那个帐号）

INTERFACE

Enter the Ethernet interface connected to the PPPoE 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): 
#输入以太网卡代号，默认是eth0(自行使用ifconfig命令即可找到)

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): 
#配置：若长时间连线，连线会被自动中断（选no表示：即使没有数据连接时也不允许中断）
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.
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: 114.114.114.114
#配置主DNS服务器（我不知道我们网络服务商的DNS，所以填写的是通用地址：114.114.114.114）
Please enter the IP address of your ISP's secondary DNS server.
If you just press enter, I will assume there is only one DNS server.
Enter the secondary DNS server address here: 8.8.8.8
#配置次DNS服务器（可以空着直接敲回车）

PASSWORD
# 两次输入账户密码以确认（上网帐号对应的密码--也是联通公司给我的那个，要输入两次，linux下键入密码时不会显示东西）
Please enter your Password: 
Please re-enter your Password: 

USERCTRL
#配置普通账户是否有网络连接权限（这里应该输入yes）
Please enter 'yes' (three letters, lower-case.) if you want to allow
normal user to start or stop DSL connection (default yes): 

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.

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
# 配置防火墙（没有特殊需求选0就OK）
Start this connection at boot time

Do you want to start this connection at boot time?
Please enter no or yes (default no):yes
#配置是否开机自动拨号连接（我选择的是yes）
** Summary of what you entered **

Ethernet Interface: eth0
User name:          990001230447
Activate-on-demand: No
Primary DNS:        114.114.114.114
Secondary DNS:      8.8.8.8
Firewalling:        NONE
User Control:       yes
Accept these settings and adjust configuration files (y/n)? y
# 确认刚填写的配置信息（没有问题的话，就选择y）
Adjusting /etc/sysconfig/network-scripts/ifcfg-ppp0
Adjusting /etc/resolv.conf
  (But first backing it up to /etc/resolv.conf.bak)
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/pppoe-status /etc/sysconfig/network-scripts/ifcfg-ppp0'
to see the link status.

pppoe-status

pppoe-start

/sbin/ifup ppp0

/sbin/ifdown ppp0