说明：
很多公司使用ADSL宽带线路作为备份线路，同时作为内部上网的分流线路。这有两种配置：一种是cisco路由器连接ethernet接口连接ADSL的modem；一种是在cisco路由器上安装ADSL WIC卡，直接连接ADSL电话线。
Cisco路由器连接ADSL modem的PPPoE配置：........................................................ 1
Cisco路由器连接ADSL WIC卡之PPPoE配置：........................................................ 3
Cisco路由器连接ADSL modem的PPPoE配置：
hostname bjsite
!
ip subnet-zero
no ip domain-lookup
!
vpdn enable
no vpdn logging
!
vpdn-group 1
request-dialin
protocol pppoe
!
interface Ethernet0/0
ip address 192.168.0.1 255.255.255.0
ip nat inside
no ip mroute-cache
!
!
!
!
interface Ethernet0/1
no ip address
pppoe enable
pppoe-client dial-pool-number 1
!
interface Dialer1
ip address negotiated
ip nat outside
ip mtu 1492
encapsulation ppp
no ip mroute-cache
dialer pool 1
dialer-group 1
ppp authentication pap
ppp pap sent-username dg48907653@163.gd password xxxxxxxx
!
ip classless
no ip http server
!
dialer-list 1 protocol ip permit
ip nat inside source list 1 interface Dialer1 overload
ip route 0.0.0.0 0.0.0.0 dialer1
access-list 1 permit 192.168.0.0 0.0.0.255
!
line con 0
exec-timeout 0 0
transport input none
line vty 0 4
login
!
end
Cisco路由器连接ADSL WIC卡之PPPoE配置：
vpdn-group pppoe
request-dialin
!--- we are the PPPoE client requesting to establish
!--- a session with the aggregation unit (6400 NRP).
protocol pppoe
!
!--- internal Ethernet network.
!
interface FastEthernet0
ip address 10.92.1.182 255.255.255.0
ip nat inside
!--- DSL interface.
!
interface ATM0
no ip address
no atm ilmi-keepalive
bundle-enable
dsl operating-mode auto
hold-queue 224 in
!--- All defaults.
!--- PPPoE runs on top of AAL5SNAP, but the
!--- encap aal5snap command is not used.
!
interface ATM0.1 point-to-point
pvc 1/1
pppoe-client dial-pool-number 1
!--- pvc 1/1 is an example value that must be changed
!--- to match the value used by the ISP.
!
!--- The PPPoE client code ties into a dialer interface upon
!--- which a virtual-access interface is cloned.
!
interface Dialer1
ip address negotiated
ip mtu 1492
!--- Ethernet MTU default = 1500 (1492 + PPPoE headers = 1500)
ip nat outside
encapsulation ppp
dialer pool 1
!--- Ties to atm interface.
ppp authentication chap callin
ppp chap hostname
ppp chap password
!
!--- The ISP will instruct you regarding
!--- the type of authentication to use.
!--- To change from PPP CHAP to PPP PAP,
!--- replace the following three lines:
!--- ppp authentication chap callin
!--- ppp chap hostname
!--- ppp chap password
!--- with the following two lines:
