MPLS VPN跨域C2 RR反射器方案

拓扑设计

拓扑介绍

如图，R9与R10分别是AS100和AS200中的RR反射器；R9与R10建立MP-BGP邻居关系，用于传递VPNV4路由，R1与R6都是PE设备，如果有多个PE设备那么配置起来相对复杂与繁琐，所以现在使用RR反射器进行配置，可以直接将路由传递给多个PE设备，减少配置命令与设备压力。

数据配置

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| ip vpn-instance vpn1 ipv4-family route-distinguisher 1:1 vpn-target 1:6 export-extcommunity vpn-target 6:1 import-extcommunity # mpls lsr-id 1.1.1.1 mpls # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 49.0000.0000.0001.00 # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip binding vpn-instance vpn1 ip address 17.1.1.1 255.255.255.0 ospf enable 1 area 0.0.0.0 # interface GigabitEthernet0/0/1 ip address 12.1.1.1 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 1.1.1.1 255.255.255.255 isis enable 1 # bgp 100 peer 9.9.9.9 as-number 100 peer 9.9.9.9 connect-interface LoopBack0 # ipv4-family unic peer 9.9.9.9 enable peer 9.9.9.9 label-route-capability # ipv4-family vpnv4 policy vpn-target peer 9.9.9.9 enable # ipv4-family vpn-instance vpn1 import-route ospf 1 |

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| mpls lsr-id 3.3.3.3 mpls lsp-trigger bgp-label-route # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 49.0000.0000.0003.00 import-route bgp # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip address 23.1.1.3 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/1 ip address 34.1.1.3 255.255.255.0 mpls # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 3.3.3.3 255.255.255.255 isis enable 1 # bgp 100 peer 9.9.9.9 as-number 100 peer 9.9.9.9 connect-interface LoopBack0 peer 34.1.1.4 as-number 200 # ipv4-family unicast undo synchronization network 1.1.1.1 255.255.255.255 network 9.9.9.9 255.255.255.255 peer 9.9.9.9 enable peer 9.9.9.9 label-route-capability peer 34.1.1.4 enable peer 34.1.1.4 route-policy 1 export peer 34.1.1.4 label-route-capability # route-policy 1 permit node 10 apply mpls-label |

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| mpls lsr-id 9.9.9.9 mpls # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 49.0000.0000.0009.00 # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip address 29.1.1.9 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/1 # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 9.9.9.9 255.255.255.255 isis enable 1 # bgp 100 peer 1.1.1.1 as-number 100 peer 1.1.1.1 connect-interface LoopBack0 peer 3.3.3.3 as-number 100 peer 3.3.3.3 connect-interface LoopBack0 peer 10.10.10.10 as-number 200 peer 10.10.10.10 ebgp-max-hop 255 peer 10.10.10.10 connect-interface LoopBack0 # ipv4-family unicast undo synchronization peer 1.1.1.1 enable peer 1.1.1.1 label-route-capability peer 3.3.3.3 enable peer 3.3.3.3 label-route-capability undo peer 10.10.10.10 enable # ipv4-family vpnv4 undo policy vpn-target peer 1.1.1.1 enable peer 1.1.1.1 next-hop-invariable peer 10.10.10.10 enable peer 10.10.10.10 next-hop-invariable |

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| mpls lsr-id 4.4.4.4 mpls lsp-trigger bgp-label-route # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 50.0000.0000.0004.00 import-route bgp # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip address 34.1.1.4 255.255.255.0 mpls # interface GigabitEthernet0/0/1 ip address 45.1.1.4 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 4.4.4.4 255.255.255.255 isis enable 1 # bgp 200 peer 10.10.10.10 as-number 200 peer 10.10.10.10 connect-interface LoopBack0 peer 34.1.1.3 as-number 100 # ipv4-family unicast undo synchronization network 6.0.0.0 network 6.6.6.6 255.255.255.255 network 10.0.0.0 network 10.10.10.10 255.255.255.255 peer 10.10.10.10 enable peer 10.10.10.10 label-route-capability peer 34.1.1.3 enable peer 34.1.1.3 route-policy 1 export peer 34.1.1.3 label-route-capability # route-policy 1 permit node 10 apply mpls-label |

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| ip vpn-instance vpn1 ipv4-family route-distinguisher 6:6 vpn-target 6:1 export-extcommunity vpn-target 1:6 import-extcommunity # mpls lsr-id 6.6.6.6 mpls # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 50.0000.0000.0006.00 # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip address 56.1.1.6 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/1 ip binding vpn-instance vpn1 ip address 68.1.1.6 255.255.255.0 ospf enable 1 area 0.0.0.0 # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 6.6.6.6 255.255.255.255 isis enable 1 # bgp 200 peer 10.10.10.10 as-number 200 peer 10.10.10.10 connect-interface LoopBack0 # ipv4-family unicast undo synchronization peer 10.10.10.10 enable peer 10.10.10.10 label-route-capability # ipv4-family vpnv4 policy vpn-target peer 10.10.10.10 enable # ipv4-family vpn-instance vpn1 import-route ospf 1 # ospf 1 vpn-instance vpn1 import-route bgp area 0.0.0.0 |

R10

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| mpls lsr-id 10.10.10.10 mpls # mpls ldp # # aaa authentication-scheme default authorization-scheme default accounting-scheme default domain default domain default_admin local-user admin password cipher % $%$ K8m.Nt84DZ}e#<0`8bmE3Uw}% $%$ local-user admin service-type http # isis 1 is-level level-2 cost-style wide network-entity 50.0000.0000.0010.00 # firewall zone Local priority 15 # interface GigabitEthernet0/0/0 ip address 15.1.1.1 255.255.255.0 isis enable 1 mpls mpls ldp # interface GigabitEthernet0/0/1 # interface GigabitEthernet0/0/2 # interface NULL0 # interface LoopBack0 ip address 10.10.10.10 255.255.255.255 isis enable 1 # bgp 200 peer 4.4.4.4 as-number 200 peer 4.4.4.4 connect-interface LoopBack0 peer 6.6.6.6 as-number 200 peer 6.6.6.6 connect-interface LoopBack0 peer 9.9.9.9 as-number 100 peer 9.9.9.9 ebgp-max-hop 255 peer 9.9.9.9 connect-interface LoopBack0 # ipv4-family unicast undo synchronization peer 4.4.4.4 enable peer 4.4.4.4 label-route-capability peer 6.6.6.6 enable peer 9.9.9.9 enable peer 9.9.9.9 next-hop-invariable peer 9.9.9.9 label-route-capability # ipv4-family vpnv4 undo policy vpn-target peer 6.6.6.6 enable peer 6.6.6.6 next-hop-invariable peer 9.9.9.9 enable peer 9.9.9.9 next-hop-invariable # |

路由传递

如图，7.7.7.7的路由传递给R6时，首先R1把R7的路由引入到MP-BGP中，MP-BGP会为这个VRF实例分配一个内层标签会被VPNV4路由携带。这条路由被R1传递给MP-IBGP邻居R9（也就是反射器），因为反射器配置了不检查RT值功能，所以他可以接收这条路由，并把这条路由继续传递给R10设备，R10也是一台RR设备，它同时也配置了不检查RT值功能，所以他也可以收到这条路由，并把路由反射给了R6设备，R6设备根据内层标签将路由传递给了VRF实例。

数据转发

R1设备查看FIB表，发现去往目的地址8.8.8.8是有隧道ID，也就意味着去往这条路由需要迭代到隧道。
在FIB表中可以看到需要迭代到去往6.6.6.6的隧道，于是按照MPLS表封装内层标签1025，并往下一跳R2转发。
现在R2设备收到了MPLS标签为1025的数据包并按照封装为1028标签继续向R3传递，R3会把LDP产生的标签弹掉之后封装策略产生的标签1028进行跨域
跨域之后继续按照隧道的标签依次传递，最终流量转发成功