华为MPLS Virtual PN option A配置&wireshark抓包分析

一、MPLS V3PN跨域OptionA

1.配置思路

1）基础配置，并在公网环境中起IGP

2）在PE与ASBR-PE建立bgp-vpnv4关系

3）在PE设备创建vpn实例绑定接口，创建RT、RD

4）在PE上配置双向重分布

5）在公网环境中配置MPLS LDP

6）在ASBR-PE上创建虚拟子接口绑定vpn实例，配置RT、RD，同时配置ASBR之间的EBGP-vpn实例的邻居关系

（实际上ASBR-PE之间传递的是纯IP包）

2.配置

javascript 复制代码

①首先实现内网的可达（配置IGP），，同时配置PE与ASBR-PE的vpnv4邻居关系
#
AR1
bgp 1
 undo default ipv4-unicast
 peer 3.3.3.3 as-number 1 
 peer 3.3.3.3 connect-interface LoopBack1
 #
 ipv4-family unicast
 undo peer 3.3.3.3 enable
 # 
 ipv4-family vpnv4
  policy vpn-target
  peer 3.3.3.3 enable
AR3
#
bgp 1
 peer 1.1.1.1 as-number 1 
 peer 1.1.1.1 connect-interface LoopBack1
 #
 ipv4-family unicast
  undo peer 1.1.1.1 enable
 # 
 ipv4-family vpnv4
  policy vpn-target
  peer 1.1.1.1 enable

②=============接着配置vpn实例（两个）=============
[R1]ip vpn-instance A 
[R1-vpn-instance-A]route-distinguisher 1:1
[R1-vpn-instance-A-af-ipv4]vpn-target 1:1
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]ip binding vpn-instance A 
[R1-GigabitEthernet0/0/0]ip add 1.1.17.1 24
[R1]ip vpn-instance B
[R1-vpn-instance-B]route-distinguisher 2:2	
[R1-vpn-instance-B-af-ipv4]vpn-target 1:2
[R1]int g0/0/1
[R1-GigabitEthernet0/0/1]ip binding vpn-instance B
[R1-GigabitEthernet0/0/1]ip add 1.1.18.1 24

③======再实现CE与PE的互通（IGP[重分布]、EBGP）=============
左边(BGP)
[R1]bgp 1
[R1-bgp]peer 1.1.17.7 as-number 7 
[R1-bgp]ipv4-family unicast 
[R1-bgp-af-ipv4]peer 1.1.17.7 enable 
[R1-bgp]peer 1.1.18.8 as-number 8
[R1-bgp]ipv4-family unicast 
[R1-bgp-af-ipv4]peer 1.1.18.8 enable 

[R1]bgp 1
[R1-bgp]ipv4-family vpn-instance A
[R1-bgp-A]peer 1.1.17.7 as-number 7
[R1-bgp]ipv4-family vpn-instance B
[R1-bgp-B]peer 1.1.18.8 as-number 8

[R7-bgp]dis this 
bgp 7
 peer 1.1.17.1 as-number 1 
 ipv4-family unicast
  network 1.1.17.0 255.255.255.0 
  network 7.7.7.7 255.255.255.255 
  peer 1.1.17.1 enable
[R8-bgp]dis this 
bgp 8
 peer 1.1.18.1 as-number 1 
 ipv4-family unicast
  network 1.1.18.0 255.255.255.0 
  network 8.8.8.8 255.255.255.255 
  peer 1.1.18.1 enable

右边(ISIS)
[R6]isis 1 vpn-instance A 
[R6-isis-1]network-entity 49.0000.0000.0000.0009.00
[R6-isis-1]is-level Level-2
[R6-isis-1]cost-style wide
[R6]isis 10 vpn-instance B
[R6-isis-10]network-entity 49.0000.0000.0000.0010.00
[R6-isis-10]cost-style wide
[R6-isis-10]is-level level-2
[R6]int g0/0/1
[R6-GigabitEthernet0/0/1]isis enable 1
[R6]int g0/0/2
[R6-GigabitEthernet0/0/2]isis enable 10

[R6]bgp 2
[R6-bgp]ipv4-family vpn-instance A
[R6-bgp-A]import-route isis 1 
[R6-bgp]ipv4-family vpn-instance B
[R6-bgp-B]import-route isis 10
[R6]isis 1 vpn-instance A
[R6-isis-1]import-route bgp 
[R6]isis 10 vpn-instance B
[R6-isis-10]import-route bgp

④==================运营商内配置MPLS LDP=================

⑤=======在ASBR-PE设备上配置创建vpn实例，创建虚拟子接口绑定==========
[R3]ip vpn-instance A
[R3-vpn-instance-A]route-distinguisher 2:2
[R3-vpn-instance-A-af-ipv4]vpn-target 1:1
[R3]ip vpn-instance B
[R3-vpn-instance-B]route-distinguisher 3:3
[R3-vpn-instance-B-af-ipv4]vpn-target 1:2

[R3]int g0/0/1.10
[R3-GigabitEthernet0/0/1.10]dot1q termination vid 10	
[R3-GigabitEthernet0/0/1.10]ip add 1.11.34.3 24
[R3-GigabitEthernet0/0/1.10]arp broadcast enable 
[R3]int g0/0/1.20
[R3-GigabitEthernet0/0/1.20]dot1q termination vid 20
[R3-GigabitEthernet0/0/1.20]ip binding vpn-instance B
[R3-GigabitEthernet0/0/1.20]ip add 1.111.34.3 24
[R3-GigabitEthernet0/0/1.20]arp broadcast enable

[R4-GigabitEthernet0/0/0.10]dis th
#
interface GigabitEthernet0/0/0.10
 dot1q termination vid 10
 ip binding vpn-instance A
 ip address 1.11.34.4 255.255.255.0 
 arp broadcast enable
[R4-GigabitEthernet0/0/0.20]dis th
[V200R003C00]
#
interface GigabitEthernet0/0/0.20
 dot1q termination vid 20
 ip binding vpn-instance B
 ip address 1.111.34.4 255.255.255.0 
 arp broadcast enable

⑥================在ASBR之间配置vpn实例的邻居关系===========
[R3-bgp-A]bgp 1
[R3-bgp]ipv4-family vpn-instance A
[R3-bgp-A]peer 1.11.34.4 as-number 2
[R3-bgp]ipv4-family vpn-instance B
[R3-bgp-B]peer 1.111.34.4 as-number 2

[R4]bgp 2
[R4-bgp]ipv4-family vpn-instance A
[R4-bgp-A]peer 1.11.34.3 as-number 1
[R4-bgp]ipv4-family vpn-instance B
[R4-bgp-B]peer 1.111.34.3 as-number 1

3.数据包转发分析

详细过程：

①CE1的流量进入PE1的vpn实例中，将ipv4路由转为vpnv4路由，接着发送给ASBR-PE1并且携带vpn标签以及下一跳为PE1

②ASBR-PE1、P1的去往PE1的路由被MPLS LDP分配

③接着ASBR-PE1将VPNv4的路由转为IPv4的路由传送给ASBR-PE2**（纯IP包）**

④ASBR-PE1的流量进入PE2的vpn实例中，将ipv4路由转为vpnv4路由，接着发送给PE2并且携带vpn标签以及下一跳为ASBR-PE2

⑤PE2、P2的去往ASBR-PE2的路由被MPLS LDP分配

⑥最后PE2将vpnv4路由转为IPv4路由发送给CE2，下一跳为PE2

数据包走向

标签转发

AR4为R7回环口分发的vpn标签为1027

AR3为R9回环口分发的vpn标签为1029

R4为7.7.7.7打上的标签 1027

R1去往R3打的LDP标签为1024

R2去往R3打的LDP标签是3（弹出标签）

R3去往R4是纯IP包

R4去往R6打的是LDP标签是1025

R5去往R6打的是LDP标签是3（弹出标签）