r1#show run
Building configuration...n
!
hostname r1
!
ip cef
!
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.0
!
!
interface Serial1/1
 ip address 192.168.1.1 255.255.255.0
 serial restart-delay 0
!
!
router rip
 network 1.0.0.0
 network 192.168.1.0
!

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r2#show run
Building configuration...

hostname r2
!
ip vrf comA
 rd 100:200
 route-target export 100:2000
 route-target import 100:2000
!
ip vrf comB
 rd 200:400
 route-target export 200:4000
 route-target import 200:4000
!
ip cef
!
!        
interface Loopback0
 ip address 2.2.2.2 255.255.255.0
 ip router isis
!
interface Serial1/0
 ip address 23.1.1.2 255.255.255.0
 ip router isis
 tag-switching ip
 serial restart-delay 0
!
interface Serial1/1
 ip vrf forwarding comA
 ip address 192.168.1.2 255.255.255.0
 serial restart-delay 0
!
interface Serial1/2
 ip vrf forwarding comB
 ip address 192.168.1.2 255.255.255.0
 serial restart-delay 0
!
router isis
 net 49.0001.0000.0000.0002.00
!
router rip
 !
 address-family ipv4 vrf comB
 redistribute bgp 100 metric 2
 network 192.168.1.0
 no auto-summary
 exit-address-family
 !
 address-family ipv4 vrf comA
 redistribute bgp 100 metric 1
 network 192.168.1.0
 no auto-summary
 exit-address-family
!
router bgp 100
 no synchronization
 bgp log-neighbor-changes
 neighbor 4.4.4.4 remote-as 100
 neighbor 4.4.4.4 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
 neighbor 4.4.4.4 activate
 neighbor 4.4.4.4 send-community both
 exit-address-family
 !
 address-family ipv4 vrf comB
 redistribute rip
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family ipv4 vrf comA
 redistribute rip
 no auto-summary
 no synchronization
 exit-address-family
!

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r3#show run
Building configuration...

hostname r3
!
!
ip cef
!
!  
interface Serial1/0
 ip address 23.1.1.3 255.255.255.0
 ip router isis
 tag-switching ip
 serial restart-delay 0
!
interface Serial1/1
 ip address 34.1.1.3 255.255.255.0
 ip router isis
 tag-switching ip
 serial restart-delay 0
!
router isis
 net 49.0001.0000.0000.0003.00
!
!        
end

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r4#show run
Building configuration...
!
hostname r4
!
!
ip vrf comA
 rd 100:200
 route-target export 100:2000
 route-target import 100:2000
!
ip vrf comB
 rd 200:200
 route-target export 200:4000
 route-target import 200:4000
!
ip cef
!
!   
interface Loopback0
 ip address 4.4.4.4 255.255.255.0
 ip router isis
!
interface Serial1/0
 ip address 34.1.1.4 255.255.255.0
 ip router isis
 tag-switching ip
 serial restart-delay 0
!
interface Serial1/1
 ip vrf forwarding comA
 ip address 192.168.2.2 255.255.255.0
 serial restart-delay 0
!
interface Serial1/2
 ip vrf forwarding comB
 ip address 192.168.2.2 255.255.255.0
 serial restart-delay 0
!
router isis
 net 49.0001.0000.0000.0004.00
!
router rip
 !
 address-family ipv4 vrf comB
 redistribute bgp 100 metric 2
 network 192.168.2.0
 no auto-summary
 exit-address-family
 !
 address-family ipv4 vrf comA
 redistribute bgp 100 metric 1
 network 192.168.2.0
 no auto-summary
 exit-address-family
!
router bgp 100
 no synchronization
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 100
 neighbor 2.2.2.2 update-source Loopback0
 no auto-summary
 !
 address-family vpnv4
 neighbor 2.2.2.2 activate
 neighbor 2.2.2.2 send-community both
 exit-address-family
 !
 address-family ipv4 vrf comB
 redistribute rip
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family ipv4 vrf comA
 redistribute rip
 no auto-summary
 no synchronization
 exit-address-family
!
!
end

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r5#show run
Building configuration...

hostname r5
!
!
ip cef
!
!  
interface Loopback0
 ip address 5.5.5.5 255.255.255.0
!
interface Serial1/1
 ip address 192.168.2.1 255.255.255.0
 serial restart-delay 0
!
router rip
 network 5.0.0.0
 network 192.168.2.0
!
!
end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r6#show run
Building configuration...

!
hostname r6
!
ip cef
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.0
!
interface Serial1/1
 ip address 192.168.1.1 255.255.255.0
 serial restart-delay 0
!
router rip
 network 1.0.0.0
 network 192.168.1.0
!
!
end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

r7#show run
Building configuration...

!
hostname r7
!
ip cef
!
interface Loopback0
 ip address 5.5.5.5 255.255.255.0
!
interface Serial1/1
 ip address 192.168.2.1 255.255.255.0
 serial restart-delay 0
!
router rip
 network 5.0.0.0
 network 192.168.2.0
!
!
end

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

配置步骤：

 

运营商骨干网准备工作
首先说说运营商骨干网准备工作，配置主要分以下几个部分：
1、在PE和P上配置IGP，使骨干网连通。
2、在PE和P上配置MPLS，启动标签交换。

1、在PE和P上配置IGP。
在此选择EIGRP/OSPF/RIP/ISIS中任意一款路由协议均可，此例中使用EIGRP。
R3：
R3(config)# router eigrp 100
R3(config-router)# network 3.3.3.3 0.0.0.0       !R3的loopback 0为3.3.3.3/32
R3(config-router)# network 10.1.1.0 0.0.0.3

R4：
R4(config)# router eigrp 100
R4(config-router)# network 10.1.1.0 0.0.0.3
R4(config-router)# network 10.1.1.4 0.0.0.3

R5：
R3(config)# router eigrp 100
R3(config-router)# network 5.5.5.5 0.0.0.0       !R5的loopback 0为5.5.5.5/32
R3(config-router)# network 10.1.1.4 0.0.0.3

2、在PE和P上配置MPLS
R3：
R3(config)# interface s1/2.1 point-to-point
R3(config-if)# description connect to R4
R3(config-if)# mpls ip

R4：
R4(config)# interface s1/2.1 point-to-point
R4(config-if)# description connect to R3
R4(config-if)# mpls ip

R4(config)# interface s1/2.2 point-to-point
R4(config-if)# description connect to R5
R4(config-if)# mpls ip

R5：
R5(config)# interface s1/2.1 point-to-point
R5(config-if)# description connect to R4
R5(config-if)# mpls ip

骨干网准备工作配置完毕！

客户端（CE）配置
接着来谈谈CE的配置，CE需要将客户的网络接入运营商，同时将自己的路由通告给PE，然后由PE通过骨干网将路由通告给该客户的其他CE。
在此例中，有两个客户：Customer_A和Customer_B，在通过MPLSVPN时，它们彼此的路由信息不会互相干扰。

CE和PE之间可以采用RIP/EIGRP/OSPF/静态路由等方式互相通告路由，CE上的配置也很简单，只需要按照以往一样启动路由协议就够了。例如：R1和R3之间运行RIPv2，那么R1的配置如下：
R1(config)# router rip
R1(config-router)# version 2
R1(config-router)# no auto-summary
R1(config-router)# nework 172.16.0.0
R1(config-router)# nework 10.0.0.0

CE的配置在此不再敷述了。

在后面的示例中，我将在两种情况下讲述PE的配置：
1、CE和PE之间运行RIPv2
2、CE和PE之间运行OSPF

其他的情况大家就自己举一反三吧。

PE的配置(CE与PE之间运行RIPv2)
PE的配置主要分为以下几个步骤：（以R3配置为例，R5配置不再敷述）
1、创建VRF。
2、在相应的将接口加入VRF。
3、配置与CE间的路由协议。
4、配置与其他PE之间的MP-BGP。
5、配置重发布。

1、创建VRF。
R3(config)# ip vrf comA
R3(config-vrf)# rd 1:27
R3(config-vrf)# route-target export 100:27
R3(config-vrf)# route-target import 100:27
       
R3(config)# ip vrf comB
R3(config-vrf)# rd 1:37
R3(config-vrf)# route-target export 100:37
R3(config-vrf)# route-target import 100:37

2、在相应的将接口加入VRF。
R3(config)# interface Serial1/2.2 point-to-point
R3(config-if)# ip vrf forwarding comA

R3(config)# interface Serial1/2.3 point-to-point
R3(config-if)# ip vrf forwarding comB

3、配置与CE间的路由协议。
R3(config)# router rip
R3(config-router)# version 2
!
R3(config-router)# address-family ipv4 vrf comB
R3(config-router-af)# network 10.0.0.0
R3(config-router-af)# no auto-summary
R3(config-router-af)# version 2
R3(config-router-af)# exit-address-family
!
R3(config-router)# address-family ipv4 vrf comA
R3(config-router-af)# network 10.0.0.0
R3(config-router-af)# no auto-summary
R3(config-router-af)# version 2
R3(config-router-af)# exit-address-family
此时可以使用show ip route vrf XXX查看虚拟路由表是否学习到客户的路由。

4、配置与R5之间的MP-BGP。
R3(config)# router bgp 100
R3(config-router)# no synchronization
R3(config-router)# neighbor 5.5.5.5 remote-as 100
R3(config-router)# neighbor 5.5.5.5 update-source Loopback0
R3(config-router)# no auto-summary
!
R3(config-router)# address-family vpnv4
R3(config-router-af)# neighbor 5.5.5.5 activate
R3(config-router-af)# neighbor 5.5.5.5 send-community both
R3(config-router-af)# exit-address-family
!
R3(config-router)# address-family ipv4 vrf comB
R3(config-router-af)# no auto-summary
R3(config-router-af)# no synchronization
R3(config-router-af)# exit-address-family
!
R3(config-router)# address-family ipv4 vrf comA
R3(config-router-af)# no auto-summary
R3(config-router-af)# no synchronization
R3(config-router-af)# exit-address-family

5、配置重发布。
R3(config)# router rip
R3(config-router)# address-family ipv4 vrf comB
R3(config-router-af)# redistribute bgp 100 metric 5
!
R3(config-router)# address-family ipv4 vrf comA
R3(config-router-af)# redistribute bgp 100 metric 5
!
R3(config)# router bgp 100
R3(config-router)# address-family ipv4 vrf comB
R3(config-router-af)# redistribute rip
!
R3(config-router)# address-family ipv4 vrf comA
R3(config-router-af)# redistribute rip

所有配置完毕。

PE的配置(CE与PE之间运行OSPF)
基本配置思想与楼上相同，这里就简单说说PE的OSPF配置和MP-BGP配置的不同点吧。

R3的OSPF与MP-BGP配置如下：

R3(config)# router ospf 1 vrf comA
R3(config-router-af)# redistribute bgp 100 subnets
R3(config-router-af)# network 10.1.1.8 0.0.0.3 area 0
!
R3(config)# router ospf 1 vrf comB
R3(config-router-af)# redistribute bgp 100 subnets
R3(config-router-af)# network 10.1.1.12 0.0.0.3 area 0

R3(config)# router bgp 100
R3(config-router)# no synchronization
R3(config-router)# neighbor 5.5.5.5 remote-as 100
R3(config-router)# neighbor 5.5.5.5 update-source Loopback0
R3(config-router)# no auto-summary
!
R3(config-router)# address-family vpnv4
R3(config-router-af)# neighbor 5.5.5.5 activate
R3(config-router-af)# neighbor 5.5.5.5 send-community both
R3(config-router-af)# exit-address-family
!
R3(config-router)# address-family ipv4 vrf comA
R3(config-router-af)# redistribute ospf 1
R3(config-router-af)# no auto-summary
R3(config-router-af)# no synchronization
R3(config-router-af)# exit-address-family
!
R3(config-router)# address-family ipv4 vrf comB
R3(config-router-af)# redistribute ospf 1
R3(config-router-af)# no auto-summary
R3(config-router-af)# no synchronization
R3(config-router-af)# exit-address-family

 

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

测试：

r1# SHOW IP RO
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

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Loopback0
R    5.0.0.0/8 [120/1] via 192.168.1.2, 00:00:14, Serial1/1
C    192.168.1.0/24 is directly connected, Serial1/1
R    192.168.2.0/24 [120/1] via 192.168.1.2, 00:00:14, Serial1/1
r1#ping 192. 
% Unrecognized host or address, or protocol not running.

r1#ping 192.168.2.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 288/344/432 ms
r1#deb
r1#debug ip pa
r1#debug ip packet
IP packet debugging is on

r2#traceroute vrf comA 192.168.2.1

Type escape sequence to abort.
Tracing the route to 192.168.2.1

  1 23.1.1.3 [MPLS: Labels 17/19 Exp 0] 112 msec 116 msec 120 msec
  2 192.168.2.2 120 msec 116 msec 120 msec
  3 192.168.2.1 192 msec *  168 msec
r2#traceroute vrf comB 192.168.2.1

Type escape sequence to abort.
Tracing the route to 192.168.2.1

  1 23.1.1.3 [MPLS: Labels 17/21 Exp 0] 100 msec 116 msec 120 msec
  2 192.168.2.2 120 msec 116 msec 120 msec
  3 192.168.2.1 192 msec *  288 msec
r2#show ip ro
r2#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

     34.0.0.0/24 is subnetted, 1 subnets
i L1    34.1.1.0 [115/20] via 23.1.1.3, Serial1/0
     2.0.0.0/24 is subnetted, 1 subnets
C       2.2.2.0 is directly connected, Loopback0
     4.0.0.0/24 is subnetted, 1 subnets
i L1    4.4.4.0 [115/30] via 23.1.1.3, Serial1/0
     23.0.0.0/24 is subnetted, 1 subnets
C       23.1.1.0 is directly connected, Serial1/0
r2#show ip ro vrf
r2#show ip ro vrf comA

Routing Table: comA
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

R    1.0.0.0/8 [120/1] via 192.168.1.1, 00:00:13, Serial1/1
B    5.0.0.0/8 [200/1] via 4.4.4.4, 00:03:25
C    192.168.1.0/24 is directly connected, Serial1/1
B    192.168.2.0/24 [200/0] via 4.4.4.4, 00:03:25
r2#show ip ro vrf comB

Routing Table: comB
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

R    1.0.0.0/8 [120/1] via 192.168.1.1, 00:00:18, Serial1/2
B    5.0.0.0/8 [200/1] via 4.4.4.4, 00:03:28
C    192.168.1.0/24 is directly connected, Serial1/2
B    192.168.2.0/24 [200/0] via 4.4.4.4, 00:03:28
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~