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

R1

ip -instance 1  ipv4-family   route-distinguisher 1:1   -target 1:6 export-extcommunity   -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 -instance 1  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 v4   policy -target   peer 9.9.9.9 enable  #  ipv4-family -instance 1   import-route ospf 1

R3

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

R9

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 v4   undo policy -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

R4

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

R6

ip -instance 1  ipv4-family   route-distinguisher 6:6   -target 6:1 export-extcommunity   -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 -instance 1  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 v4   policy -target   peer 10.10.10.10 enable  #  ipv4-family -instance 1   import-route ospf 1 # ospf 1 -instance 1  import-route bgp  area 0.0.0.0

R10

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 v4   undo policy -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

1. 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。
2. 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。
   
3. 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
4. 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