第一步：配置客户端
Client(config)#int f0/0
Client(config-if)#no sh
Client(config-if)#pppoe enable
//在接口下开启PPPoE 服务
Client(config-if)#pppoe-client dial-pool-number 1
//定义这个接口为PPPoE客户端，拨号地址池号为1(这个与下面必须相符合)
Client(config)#int dialer 0
//进入拨号0口的配置模式
Client(config-if)#ip add negotiated
//配置ip地址类型为协商
Client(config-if)#encapsulation ppp
//定义封装类型为PPP
Client(config-if)#dialer pool 1
//定义拨号地址为1，必须与上面相符
Client(config-if)#ppp chap hostname admin
Client(config-if)#ppp chap password admin
//以上两步为定义帐户名和密码
Client(config)#ip route 0.0.0.0 0.0.0.0 dialer 0
//一条出外网的静态路由
第二步：配置服务端
Server(config)#username admin password admin
//定义一个用户名与密码，客户端用这个用户名与密码登录
Server(config)#vpdn enable
//开启虚拟专用拨号网络
Server(config)#vpdn-group ?
WORD VPDN Group name
Server(config)#vpdn-group 1
//定义vpdn组名称，我们在这里定义组名为1，但是在show run里没有显示
Server(config-vpdn)#accept-dialin
//定义接受拨号
Server(config-vpdn-acc-in)#protocol pppoe
//定义协议为PPPoE
% PPPoE config from vpdn-group is converted to pppoe-profile based config.
% Continue PPPoE configuration under 'bba-group pppoe global'
Server(config-vpdn-acc-in)#exi
Server(config-vpdn)#exi
Server(config)#bba-group pppoe global
//进入PPPoE全局配置模式
Server(config-bba-group)#virtual-template 1
//创建一个虚模板
Server(config-bba-group)#exi
Server(config)#
Server(config)#int f0/0
Server(config-if)#no ip add
Server(config-if)#pppoe enable
Server(config-if)#no sh
Server(config)#int virtual-template 1
Server(config-if)#ip add 10.0.0.1 255.255.255.0
Server(config-if)#peer default ip address pool libo
Server(config-if)#ppp authentication chap
Server(config-if)#exi
Server(config)#ip local pool libo 10.0.0.10 10.0.0.20
第三步：debug过程
接下来我们看看PPPoE的发现和建立，在服务器端
debug pppoe events
May 10 21:17:19.943: PPPoE 0: I PADI R:ca03.0cb4.0008 L:ffff.ffff.ffff Fa0/0
May 10 21:17:19.943: Service tag: NULL Tag
//以上为PPPoE的PADI阶段(初始化阶段，查找PPPoE服务器)，源mac地址为本地F0/0接口的地址，目标为全F，即广播地址
May 10 21:17:19.943: PPPoE 0: O PADO, R:ca04.0cb4.0008 L:ca03.0cb4.0008 Fa0/0
May 10 21:17:19.947: Service tag: NULL Tag
//以上为PPPoE的PADO阶段，单播回应，源mac为Server的F0/0
May 10 21:17:21.959: PPPoE 0: I PADR R:ca03.0cb4.0008 L:ca04.0cb4.0008 Fa0/0
May 10 21:17:21.959: Service tag: NULL Tag
May 10 21:17:21.959: PPPoE : encap string prepared
May 10 21:17:21.963: [4]PPPoE 3: Access IE handle allocated
May 10 21:17:21.963: [4]PPPoE 3: pppoe SSS switch updated
May 10 21:17:21.963: [4]PPPoE 3: AAA unique ID allocated
May 10 21:17:21.963: [4]PPPoE 3: No AAA accounting method list
May 10 21:17:21.967: [4]PPPoE 3: Service request sent to SSS
May 10 21:17:21.967: [4]PPPoE 3: Created, Service: None R:ca04.0cb4.0008 L:ca03.0cb4.0008 Fa0/0
May 10 21:17:21.971: [4]PPPoE 3: State NAS_PORT_POLICY_INQUIRY Event MORE_KEYS
//以上为PPPoE的PADR阶段，单播请求建立链接
May 10 21:17:21.975: [4]PPPoE 3: O PADS R:ca03.0cb4.0008 L:ca04.0cb4.0008 Fa0/0
May 10 21:17:21.979: [4]PPPoE 3: State PPP_START Event DYN_BIND
*May 10 21:17:21.983: [4]PPPoE 3: data path set to PPP
//以上为PADS阶段，如果用户名和密码正确，则分配ip地址，开始连入网络
May 10 21:17:24.175: [4]PPPoE 3: State LCP_NEGOTIATION Event PPP_LOCAL
May 10 21:17:24.179: PPPoE 3/SB: Sent vtemplate request on base Vi1
May 10 21:17:24.199: [4]PPPoE 3: State VACCESS_REQUESTED Event VA_RESP
May 10 21:17:24.199: [4]PPPoE 3: Vi1.1 interface obtained
May 10 21:17:24.203: [4]PPPoE 3: State PTA_BINDING Event STAT_BIND
May 10 21:17:24.203: [4]PPPoE 3: data path set to Virtual Acess
*May 10 21:17:24.203: [4]PPPoE 3: Connected PTA
//备注：这里还有一个PADT的阶段，这个为不成功，这里就不做演示了，如果学者用GNS3做实验的话，如果内在不够的话，会出现PADS--PADT
R1-client#sh ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset up up
FastEthernet0/1 unassigned YES unset administratively down down
Virtual-Access1 unassigned YES unset up up
Virtual-Access2 unassigned YES unset up up
Dialer0 10.0.0.10 YES IPCP up up
R1-server#sh ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 unassigned YES unset up up
FastEthernet0/1 unassigned YES unset administratively down down
Virtual-Access1 unassigned YES unset up up
Virtual-Access1.1 10.0.0.1 YES TFTP up up
Virtual-Template1 10.0.0.1 YES manual down down
Virtual-Access2 unassigned YES unset down down
第四步：配置客户端的PAT
接下来配置PAT
Client(config)#int f0/1
Client(config-if)#ip add 192.168.0.1 255.255.255.0
Client(config-if)#ip nat inside
Client(config-if)#no sh
//定义inside接口
Client(config)#int dialer 0
Client(config-if)#ip nat outside
//定义outsie端
Client(config)#access-list 1 permit any
Client(config)#ip nat inside source list 1 interface dialer 0
//对list进行关联
Client(config)#ip dhcp pool libo
Client(dhcp-config)#network 192.168.0.0 /24
Client(dhcp-config)#default-router 192.168.0.1
Client(config)#ip dhcp excluded-address 192.168.0.1 192.168.0.9
//以上为地址池的定义过程
第五步：配置pc
来看看pc上的配置
pc3(config)#int f0
pc3(config-if)#ip add dhcp
pc3(config-if)#no sh
pc3(config)#ip default-gateway 192.168.0.1
第六步：测试
pc3#sh ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0 192.168.0.10 YES DHCP up up
//上面可以看出接口通过DHCP获得到了ip地址
测试
pc3# ping 1.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 48/79/100 ms
pc3#1.1.1.1
Trying 1.1.1.1 ... Open
Server>exi
[Connection to 1.1.1.1 closed by foreign host]
Client#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 10.0.0.10:0 192.168.0.10:0 1.1.1.1:0 1.1.1.1:0
tcp 10.0.0.10:11000 192.168.0.10:11000 1.1.1.1:23 1.1.1.1:23
//上面可以看到PAT成功转换