实验环境：
GNS3 0.6
模拟CISCO 7200 ，IOS使用 c7200-advipservicesk9_li-mz.124-11.t.bin
R0的F0/0连接cloud0，F1/0连接cloud1
Cloud0桥接到物理网卡，cloud1桥接到loopback网卡
VPC虚拟两台客户端client1，client2分别桥接到物理网卡和loopback网卡上
R 0 F 0/0： 10.10.10 .10/ 24 F 1/0：172.16.1.1/24
Client1： 10.10.10 .100/24 default gateway：10.10.10.10
Client2：172.16.1.100/24 default gateway：172.16.1.1
R0上配置：
Connected to Dynamips VM "R0" (ID 0, type c7200) - Console port
% Please answer 'yes' or 'no'.
Would you like to enter the initial configuration dialog? [yes/no]: n
Press RETURN to get started!
Router>en
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#int f0/0
Router(config-if)#ip add 10.10.10 .10 255.255.255.0
Router(config-if)#no shut
Router(config-if)#
*May 15 03:05:35.659: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
*May 15 03:05:35.663: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/0 Physical Port Administrative State Down
*May 15 03:05:36.659: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
Router(config-if)#int f1/0
Router(config-if)#ip add 172.16.1.1 255.255.255.0
Router(config-if)#no shut
Router(config-if)#
*May 15 03:06:01.599: %LINK-3-UPDOWN: Interface FastEthernet1/0, changed state to up
*May 15 03:06:01.603: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa1/0 Physical Port Administrative State Down
*May 15 03:06:02.599: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0, changed state to up
Router(config-if)#exit
Router(config)#no ip domain-lookup
Router(config)#username cisco password cisco
Router(config)#ip local pool dhpool 192.168.1.100 192.168.1.200
Router(config)#vpdn enable
Router(config)#vpdn-group vpdn
Router(config-vpdn)#accept-dialin
Router(config-vpdn-acc-in)#protocol pptp
Router(config-vpdn-acc-in)#virtual-template 1
Router(config-vpdn-acc-in)#exit
Router(config-vpdn)#exit
Router(config)#int virtual-template 1
Router(config-if)#ip add 192.168.1.254 255.255.255.0
Router(config-if)#peer default ip add pool dhpool
Router(config-if)#ppp encrypt mppe 40
Router(config-if)#ppp authentication ms-chap
Router(config-if)#exit
Router(config)#exit
Router#
*May 15 03:41:26.339: %SYS-5-CONFIG_I: Configured from console by console
Router#write memory
Building configuration...
[OK]
Router#
Client1上创建×××连接：
运行“rasphone”，
测试
×××
连接：
