试验预备知识：
首先建议大家先了解ATM是什么？了解一下ATM周边知识点，给出如下两个链接
ATM协议大全 [url]http://www.cnpaf.net/class/atm/[/url]
那些是ATM？[url]http://baike.baidu.com/view/26.htm[/url]
 
实验过程：
第一步  ATM1的预配置
ATM1(config)# username cisco password cisco
ATM1(config)# int f3/0
ATM1(config-if)# pppoe enable
ATM1(config-if)# no sh
ATM1(config)#
第二步  配置VPDN
ATM1(config)# vpdn enable
ATM1(config)# vpdn-group adsl
ATM1(config-vpdn)# request-dialin
ATM1(config-vpdn-req-in)# protocol pppoe
% PPPoE config from vpdn-group is converted to pppoe-profile based config.
% Continue PPPoE configuration under 'bba-group pppoe global'
ATM1(config-vpdn-req-in)# exit
ATM1(config-vpdn)# exit
第三步  配置BBA-Group
ATM1(config)# bba-group pppoe global
ATM1(config-bba-group)# virtual-template 1
ATM1(config-bba-group)# exit
第四步  配置Virtual-Template接口
ATM1(config)# interface virtual-template 1
ATM1(config-if)# ip add 10.0.0.1 255.255.255.0
ATM1(config-if)# encapsulation ppp
ATM1(config-if)# ppp authentication pap
ATM1(config-if)# peer default ip address pool adsl
ATM1(config-if)# exit
ATM1(config)# ip local pool adsl 10.0.0.10 10.0.0.100
第五步  创建一个PPPoE连接，打开并连接
第六步  拨号成功后查看PPPoE的连接状态，可以看到本地的IP地址与服务器的IP地址

第七步  同时在WireShark中抓下PPPoE拨号的过程

第八步  在ATM1上查看PPPoE的调试信息
ATM1# debug pppoe events
PPPoE protocol events debugging is on
ATM1#
//  开始进行PPPoE的拨号
*Jun 16 15:49:22.103: PPPoE 2: I PADT  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:49:22.107: [2]PPPoE 2: Destroying  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:49:22.107: PPPoE: Returning Vaccess Virtual-Access1.1
*Jun 16 15:49:22.115: [2]PPPoE 2: AAA account stopped
ATM1#
*Jun 16 15:49:32.727: PPPoE 0: I PADI  R:0013.e8a5.d445 L:ffff.ffff.ffff Fa3/0
*Jun 16 15:49:32.727:  Service tag: NULL Tag
*Jun 16 15:49:32.727: PPPoE 0: O PADO, R:caff.09e4.0054 L:0013.e8a5.d445 Fa3/0
*Jun 16 15:49:32.731:  Service tag: NULL Tag
*Jun 16 15:49:32.751: PPPoE 0: I PADR  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:49:32.751:  Service tag: NULL Tag
*Jun 16 15:49:32.755: PPPoE : encap string prepared
*Jun 16 15:49:32.755: [3]PPPoE 3: Access IE handle allocated
*Jun 16 15:49:32.755: [3]PPPoE 3: pppoe SSS switch updated
*Jun 16 15:49:32.755: [3]PPPoE 3: AAA unique ID allocated
*Jun 16 15:49:32.759: [3]PPPoE 3: No AAA accounting method list
*Jun 16 15:49:32.759: [3]PPPoE 3: Service request sent to SSS
*Jun 16 15:49:32.763: [3]PPPoE 3: Created, Service: None R:caff.09e4.0054 L:0013.e8a5.d445 Fa3/0
*Jun 16 15:49:32.767: [3]PPPoE 3: State NAS_PORT_POLICY_INQUIRY    Event MORE_KEYS
*Jun 16 15:49:32.767: [3]PPPoE 3: O PADS  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:49:32.779: [3]PPPoE 3: State PPP_START    Event DYN_BIND
*Jun 16 15:49:32.779: [3]PPPoE 3: data path set to PPP
*Jun 16 15:49:32.903: [3]PPPoE 3: State LCP_NEGOTIATION    Event PPP_LOCAL
*Jun 16 15:49:32.903: PPPo
ATM1#E 3/SB: Sent vtemplate request on base Vi1
*Jun 16 15:49:32.935: [3]PPPoE 3: State VACCESS_REQUESTED    Event VA_RESP
*Jun 16 15:49:32.935: [3]PPPoE 3: Vi1.1 interface obtained
*Jun 16 15:49:32.939: [3]PPPoE 3: State PTA_BINDING    Event STAT_BIND
*Jun 16 15:49:32.939: [3]PPPoE 3: data path set to Virtual Acess
*Jun 16 15:49:32.943: [3]PPPoE 3: Connected PTA
ATM1#
ATM1# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
     10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C       10.0.0.10/32 is directly connected, Virtual-Access1.1
//  在ATM1上可以看到PPPoE Client的路由
C       10.0.0.0/24 is directly connected, Virtual-Access1.1
ATM1#
ATM1#
//  现在断开PPPoE客户端
*Jun 16 15:50:56.231: PPPoE 3: I PADT  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:50:56.235: [3]PPPoE 3: Destroying  R:0013.e8a5.d445 L:caff.09e4.0054 Fa3/0
*Jun 16 15:50:56.235: PPPoE: Returning Vaccess Virtual-Access1.1
*Jun 16 15:50:56.243: [3]PPPoE 3: AAA account stopped
ATM1# debug pppoe packets
 //  调试PPPoE数据包
PPPoE control packets debugging is on
ATM1#
*Jun 16 16:21:05.711: PPPoE 0: I PADI  R:0013.e8a5.d445 L:ffff.ffff.ffff Fa3/0
         FF FF FF FF FF FF 00 13 E8 A5 D4 45 88 63 11 09
         00 00 00 10 01 01 00 00 01 03 00 08 0E 00 00 00 ...
*Jun 16 16:21:05.715: PPPoE 0: O PADO, R:caff.00b8.0054 L:0013.e8a5.d445 Fa3/0
*Jun 16 16:21:05.719:  Service tag: NULL Tag
         00 13 E8 A5 D4 45 CA FF 00 B8 00 54 88 63 11 07
         00 00 00 2C 01 01 00 00 01 03 00 08 0E 00 00 00 ...
*Jun 16 16:21:05.775: PPPoE 0: I PADR  R:0013.e8a5.d445 L:caff.00b8.0054 Fa3/0
         CA FF 00 B8 00 54 00 13 E8 A5 D4 45 88 63 11 19
         00 00 00 24 01 01 00 00 01 03 00 08 0E 00 00 00 ...
*Jun 16 16:21:05.783: [4]PPPoE 4: O PADS  R:0013.e8a5.d445 L:caff.00b8.0054 Fa3/0
ATM1#
         00 13 E8 A5 D4 45 CA FF 00 B8 00 54 88 63 11 65
         00 04 00 24 01 01 00 00 01 03 00 08 0E 00 00 00 ...
ATM1#
ATM1# debug ppp authentication
//  调试PPP认证信息
PPP authentication debugging is on
ATM1#
*Jun 16 16:19:44.099: ppp3 PPP: Using *** set call direction
*Jun 16 16:19:44.099: ppp3 PPP: Treating connection as a callin
*Jun 16 16:19:44.099: ppp3 PPP: Session handle[C5000005] Session id[3]
ATM1#
*Jun 16 16:19:46.111: ppp3 PPP: Authorization required
*Jun 16 16:19:46.427: ppp3 PAP: I AUTH-REQ id 8 len 16 from "cisco"
*Jun 16 16:19:46.427: ppp3 PAP: Authenticating peer cisco
*Jun 16 16:19:46.439: ppp3 PPP: Sent PAP LOGIN Request
*Jun 16 16:19:46.443: ppp3 PPP: Received LOGIN Response PASS
*Jun 16 16:19:46.495: Vi1.1 PPP: Sent LCP AUTHOR Request
*Jun 16 16:19:46.499: Vi1.1 PPP: Sent IPCP AUTHOR Request
*Jun 16 16:19:46.507: Vi1.1 LCP: Received AAA AUTHOR Response PASS
*Jun 16 16:19:46.507: Vi1.1 IPCP: Received AAA AUTHOR Response PASS
*Jun 16 16:19:46.511: Vi1.1 PAP: O AUTH-ACK id 8 len 5
ATM1#