MPLS ×××跨域实现之OPTION B配置讲解

MPLS ××× OPTION B 配置讲解

 

 

 

一般资料介绍跨域 MPLS/××× OPTION_B 时，采用两个 AS ，为加深理解，本例采用三个 AS ，其中中间 AS300 为传送 AS ，不启 MPLS 标签交换，只通过 MP — EBGP 传送 ×××V4 的私网路由。实验中模拟路由器均采用 Cisco 7206 。

数据规划：

1、              设备互联：

Router1 S1/0 <----> Router2 S1/0

Router 2 F 0/0 <----> Router 3 F 0/0

Router3 S1/1 <----> Router4 S1/1

Router 4 F 0/0 <----> Router 5 F 0/0

Router5 S1/1 <----> Router6 S1/1

2、              地址规划：设备互连地址 10.10.XY.X/24 （ R1 中 X=1,R1 与 R2 互联 Y=2 ，其余类推）。

          Loopback 0 地址为： X.X.X.X/32

          ××× 地址：

R1 中 ***a ： 172.16.1.1/24

      ***b: 192.168.1.1/24

R6 中 ***a ： 172.16.2.1/24

      ***b: 192.168.2.1/24

3、              ××× 规划：在 R1 和 R6 中采用 loopback 11 /loopback22 模拟 ×××A 和 ×××B, 简化了 PE — CE 间配置。

          ×××A: RD  100:10

               ROUTE-TARGET 100:10

          ×××B: RD  100:20

               ROUTE-TARGET 100:20

4、              IGP 路由协议： AS120 采用 OSPF ， AS456 采用 ISIS 。  

 

配置基本思路：

1、 在完成 IGP 等基本配置后，在所有 PE 设备和 P 设备上启用 IP  CEF 。

2、  在所有 PE 设备和 P 设备上启用 MPLS  IP 。

3、   AS120/AS456 中 PE 和 ASBR 建立 BGP 邻居关系。

4、    PE 中创建 ××× ，并在 PE — CE 间接口使能 VRF  FORWARDING 。

5 、 PE 中 BGP  IPV4  VRF 地址族中发布 ××× 路由。

6 、 AS120/AS456 中 PE 和 ASBR 建立 BGP  ×××V4 邻居关系，交换 ××× 路由信息。

7 、 AS120/AS456 中 ASBR 分别和传送区域 AS300 中 ASBR 建立 ×××V4 邻居关系，传送 ×××V4 路由。（注意： AS300 中的 R3 与 R1 或 R6 之间并没有 IPV4 的路由，在由 R2 和 R4 向 R3 发送 ××× 路由时，必须把收到的 R1 和 R6 的 ××× 路由的下一跳强制指向自己，使用 next-hop self 命令，否则 R3 会认为该路由不可达，从而丢弃。）

8 、要允许的 ASBR 接受所有的 ×××V4 前缀，必须禁用缺省的 ARF 。可以通过在所有的 ×××V4  ASBR 上配置 no bgp default route-target filter 来完成。

 

 

配置脚本如下：

R1#show run
Building configuration...

Current configuration : 1985 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
ip vrf ***a
 rd 100:10
 route-target export 100:10
 route-target import 100:10
!
ip vrf ***b
 rd 100:20
 route-target export 100:20
 route-target import 100:20
!
mpls label range 100 199
mpls label protocol ldp
tag-switching tdp router-id Loopback0 force
!
!
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
 no ip directed-broadcast
!
interface Loopback11
 ip vrf forwarding ***a
 ip address 172.16.1.1 255.255.255.0
 no ip directed-broadcast
!
interface Loopback22
 ip vrf forwarding ***b
 ip address 192.168.1.1 255.255.255.0
 no ip directed-broadcast
!
interface FastEthernet0/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/0
 ip address 10.10.12.1 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/1
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 1.1.1.1 0.0.0.0 area 0
 network 10.10.12.0 0.0.0.255 area 0
!
router bgp 120
 no synchronization
 bgp router-id 1.1.1.1
 bgp log-neighbor-changes
 neighbor 2.2.2.2 remote-as 120
 neighbor 2.2.2.2 update-source Loopback0
 neighbor 2.2.2.2 send-label explicit-null
 no auto-summary
 !
 address-family ***v4
 neighbor 2.2.2.2 activate
 neighbor 2.2.2.2 send-community extended
 exit-address-family
 !       
 address-family ipv4 vrf ***b
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family ipv4 vrf ***a
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end

R1#

R2>en
R2#show run
Building configuration...

Current configuration : 1540 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
mpls label range 200 299
mpls label protocol ldp
tag-switching tdp router-id Loopback0 force
!
!
!        
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
 no ip directed-broadcast
!
interface FastEthernet0/0
 ip address 10.10.23.2 255.255.255.0
 no ip directed-broadcast
 mpls bgp forwarding
!
interface Serial1/0
 ip address 10.10.12.2 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/1
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 2.2.2.2 0.0.0.0 area 0
 network 10.10.12.0 0.0.0.255 area 0
!
router bgp 120
 no synchronization
 bgp router-id 2.2.2.2
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 1.1.1.1 remote-as 120
 neighbor 1.1.1.1 update-source Loopback0
 neighbor 10.10.23.3 remote-as 300
 no auto-summary
 !
 address-family ***v4
 neighbor 1.1.1.1 activate
 neighbor 1.1.1.1 send-community extended
 neighbor 1.1.1.1 next-hop-self
 neighbor 10.10.23.3 activate
 neighbor 10.10.23.3 send-community extended
 exit-address-family
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end      

R2#

R3#show run
Building configuration...

Current configuration : 1245 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R3
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
no tag-switching ip
!
!
!
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
 no ip directed-broadcast
!
interface FastEthernet0/0
 ip address 10.10.23.3 255.255.255.0
 no ip directed-broadcast
 mpls bgp forwarding
!
interface Serial1/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/1
 ip address 10.10.34.3 255.255.255.0
 no ip directed-broadcast
 mpls bgp forwarding
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router bgp 300
 no synchronization
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 10.10.23.2 remote-as 120
 neighbor 10.10.34.4 remote-as 456
 no auto-summary
 !
 address-family ***v4
 neighbor 10.10.23.2 activate
 neighbor 10.10.23.2 send-community extended
 neighbor 10.10.34.4 activate
 neighbor 10.10.34.4 send-community extended
 exit-address-family
!
ip classless
!
!
!        
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end

R3#

R4#show run
Building configuration...

Current configuration : 1517 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R4
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
mpls label range 400 499
mpls label protocol ldp
tag-switching tdp router-id Loopback0 force
!
!
!        
interface Loopback0
 ip address 4.4.4.4 255.255.255.255
 no ip directed-broadcast
!
interface FastEthernet0/0
 ip address 10.10.45.4 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/1
 ip address 10.10.34.4 255.255.255.0
 no ip directed-broadcast
 mpls bgp forwarding
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 4.4.4.4 0.0.0.0 area 0
 network 10.10.45.0 0.0.0.255 area 0
!
router bgp 456
 no synchronization
 no bgp default route-target filter
 bgp log-neighbor-changes
 neighbor 6.6.6.6 remote-as 456
 neighbor 6.6.6.6 update-source Loopback0
 neighbor 10.10.34.3 remote-as 300
 no auto-summary
 !
 address-family ***v4
 neighbor 6.6.6.6 activate
 neighbor 6.6.6.6 send-community extended
 neighbor 6.6.6.6 next-hop-self
 neighbor 10.10.34.3 activate
 neighbor 10.10.34.3 send-community extended
 exit-address-family
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end
         
R4#
R5#show run
Building configuration...

Current configuration : 1098 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R5
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
mpls label range 500 599
mpls label protocol ldp
tag-switching tdp router-id Loopback0
!
!
!        
interface Loopback0
 ip address 5.5.5.5 255.255.255.255
 no ip directed-broadcast
!
interface FastEthernet0/0
 ip address 10.10.45.5 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/1
 ip address 10.10.56.5 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 5.5.5.5 0.0.0.0 area 0
 network 10.10.45.0 0.0.0.255 area 0
 network 10.10.56.0 0.0.0.255 area 0
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end

R5#      

R6#show run
Building configuration...

Current configuration : 1962 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R6
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
ip vrf ***a
 rd 100:10
 route-target export 100:10
 route-target import 100:10
!
ip vrf ***b
 rd 100:20
 route-target export 100:20
 route-target import 100:20
!
mpls label range 600 699
mpls label protocol ldp
tag-switching tdp router-id Loopback0 force
!
!
!
interface Loopback0
 ip address 6.6.6.6 255.255.255.255
 no ip directed-broadcast
!
interface Loopback11
 ip vrf forwarding ***a
 ip address 172.16.2.1 255.255.255.0
 no ip directed-broadcast
!
interface Loopback22
 ip vrf forwarding ***b
 ip address 192.168.2.1 255.255.255.0
 no ip directed-broadcast
!
interface FastEthernet0/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/1
 ip address 10.10.56.6 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 6.6.6.6 0.0.0.0 area 0
 network 10.10.56.0 0.0.0.255 area 0
!
router bgp 456
 no synchronization
 bgp log-neighbor-changes
 neighbor 4.4.4.4 remote-as 456
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 send-label explicit-null
 no auto-summary
 !
 address-family ***v4
 neighbor 4.4.4.4 activate
 neighbor 4.4.4.4 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf ***b
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family ipv4 vrf ***a
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end

R6#            show run
Building configuration...

Current configuration : 1962 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname R6
!
boot-start-marker
boot-end-marker
!
!
ip subnet-zero
!
!
ip cef
ip vrf ***a
 rd 100:10
 route-target export 100:10
 route-target import 100:10
!
ip vrf ***b
 rd 100:20
 route-target export 100:20
 route-target import 100:20
!
mpls label range 600 699
mpls label protocol ldp
tag-switching tdp router-id Loopback0 force
!
!
!
interface Loopback0
 ip address 6.6.6.6 255.255.255.255
 no ip directed-broadcast
!
interface Loopback11
 ip vrf forwarding ***a
 ip address 172.16.2.1 255.255.255.0
 no ip directed-broadcast
!
interface Loopback22
 ip vrf forwarding ***b
 ip address 192.168.2.1 255.255.255.0
 no ip directed-broadcast
!
interface FastEthernet0/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/0
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/1
 ip address 10.10.56.6 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
!
interface Serial1/2
 no ip address
 no ip directed-broadcast
 shutdown
!
interface Serial1/3
 no ip address
 no ip directed-broadcast
 shutdown
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 6.6.6.6 0.0.0.0 area 0
 network 10.10.56.0 0.0.0.255 area 0
!
router bgp 456
 no synchronization
 bgp log-neighbor-changes
 neighbor 4.4.4.4 remote-as 456
 neighbor 4.4.4.4 update-source Loopback0
 neighbor 4.4.4.4 send-label explicit-null
 no auto-summary
 !
 address-family ***v4
 neighbor 4.4.4.4 activate
 neighbor 4.4.4.4 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf ***b
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
 !
 address-family ipv4 vrf ***a
 redistribute connected
 no auto-summary
 no synchronization
 exit-address-family
!
ip classless
!
!
!
control-plane
!
!
line con 0
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
no cns aaa enable
end

R6#