步骤概述：
1、搜寻PPPoE相关软件，本人使用的是rp-pppoe
yum search pppoe
2、使用yum安装rp-pppoe
yum install rp-pppoe -y
3、开始配置PPPoE连接
pppoe-setup
4、输入ISP提供的账户
5、输入以太网卡代号，默认是eth0（注：CentOS 7已不是默认eth0，自行使用ifconfig命令即可找到）
6、配置：若长时间连线，连线会被自动中断（我不干，选no）
7、配置主DNS服务器
8、配置次DNS服务器
9、两次输入账户密码以确认
10、配置普通账户是否有网络连接权限
11、配置防火墙（没有特殊需求选0就OK）
12、配置是否开机自动拨号连接
13、确认刚填写的配置信息
14、连接网络尽情享受吧！
相关命令@ 连接网络：/sbin/ifup ppp0，断开连接：/sbin/ifdown ppp0，查看网络状态：/sbin/pppoe-status
....................................... 这是华丽丽的分割线 .......................................
获取以太网卡代号
[dsp@dsp Desktop]$ ifconfig
enp9s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 # 有线网卡
ether 20:1b:06:3d:22:05 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 2297 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 18
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 2 bytes 110 (110.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2 bytes 110 (110.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:36:45:23 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp8s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 # 无线网卡
inet 192.168.0.151 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::4ad2:24ff:fee8:f962 prefixlen 64 scopeid 0x20<link>
ether 48:d2:24:e8:f9:62 txqueuelen 1000 (Ethernet)
RX packets 20017 bytes 16100210 (15.3 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18263 bytes 2641746 (2.5 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
配置rp-pppoe客户端
[root@dsp Desktop]# 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 dsp): 12345 # 网络服务提供商提供的账户
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): enp9s0 # 选择以太网卡，有线网卡
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): no # 输入no，否则若长时间连线，连线会被自动中断
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: 8.8.8.8 # 主DNS服务器IP，本人使用Google Public DNS
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: 8.8.4.4 # 二级DNS服务器IP
PASSWORD # 账户对应的密码，需两次输入以确认无误
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): yes # 普通用户是否可以启动停止网络连接
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 # 选 0 吧
Start this connection at boot time
Do you want to start this connection at boot time?
Please enter no or yes (default no):yes # 是否系统启动是就连接网络
** Summary of what you entered **
Ethernet Interface: enp9s0
User name: 12345
Activate-on-demand: No
Primary DNS: 8.8.8.8
Secondary DNS: 8.8.4.4
Firewalling: NONE
User Control: yes
Accept these settings and adjust configuration files (y/n)? y # 确认刚才输入的网络配置信息
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' # rp-pppoe的操作命令
to bring it down.
Type '/sbin/pppoe-status /etc/sysconfig/network-scripts/ifcfg-ppp0'
to see the link status.
[root@dsp Desktop]# /sbin/ifup ppp0 # 启动网络连接
[root@dsp Desktop]# /sbin/pppoe-status # 查看网络连接状态
pppoe-status: Link is up and running on interface ppp0
6: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast state UNKNOWN qlen 3
link/ppp
inet 10.198.0.17 peer 10.198.1.1/32 scope global ppp0
valid_lft forever preferred_lft forever