没有路由器的情况下，linux也是需要拨号上网的。
从安装光盘Packages中取出下面三个包
libpcap-1.4.0-4.20130826git2dbcaa1.el6.x86_64.rpm
ppp-2.4.5-10.el6.x86_64.rpm
rp-pppoe-3.10-16.el6.x86_64.rpm
使用rpm -ivh 安装
# rpm -ivh libpcap-1.4.0-4.20130826git2dbcaa1.el6.x86_64.rpm ppp-2.4.5-10.el6.x86_64.rpm ppp-2.4.5-10.el6.x86_64.rpm warning: package ppp = 2.4.5-10.el6 was already added, skipping ppp = 2.4.5-10.el6 Preparing... ########################################### [100%] 1:libpcap ########################################### [ 50%] 2:ppp ########################################### [100%]
进入/usr/sbin/ 执行 adsl-setup进行配置
# /usr/sbin/adsl-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): 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): 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): 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: server PASSWORD Please enter your Password: [root@as home]# /usr/sbin/adsl-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): 此处填写宽带帐号 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): 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): 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: PASSWORD Please enter your Password: Please re-enter your Password: USERCTRL 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 Start this connection at boot time Do you want to start this connection at boot time? Please enter no or yes (default no):yes ** Summary of what you entered ** Ethernet Interface: eth0 User name: 此处为宽带帐号 Activate-on-demand: No DNS: Do not adjust Firewalling: NONE User Control: yes Accept these settings and adjust configuration files (y/n)? y 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/pppoe-status /etc/sysconfig/network-scripts/ifcfg-ppp0‘ to see the link status.
启动adsl -start
停止adsl -stop
原文：http://yikaka.blog.51cto.com/2450049/1889067