配置BGP邻居的建立

PE1和RR1建立IBGP邻居、RR1和ASBR1建立IBGP邻居（RR1作为反射器）

PE1和RR1建立MP-IBGP邻居（RR1传给PE1的Vpnv4路由要求更改下一跳-默认）

ASBR1和ASBR2建立EBGP邻居

ASBR2和RR2建立IBGP邻居、RR2和PE2建立IBGP邻居（RR2作为反射器）

PE2和RR2建立MP-IBGP邻居（RR2传给PE2的Vpnv4路由要求更改下一跳-默认）

PE1和RR1建立IBGP邻居（RR1为反射器）和MP-IBGP邻居

PE1

bgp 100

peer 7.7.7.7 as-number 100

peer 7.7.7.7 connect-interface LoopBack0

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ipv4-family unicast

undo synchronization

peer 7.7.7.7 enable

ipv4-family vpnv4

policy vpn-target

peer 7.7.7.7 enable

RR1

bgp 100

peer 1.1.1.1 as-number 100

peer 1.1.1.1 connect-interface LoopBack0

ipv4-family unicast

peer 1.1.1.1 enable

peer 1.1.1.1 reflect-client                      配置1.1.1.1为反射客户端（本端为反射器）

ipv4-family vpnv4

undo policy vpn-target                          取消RT值检测

peer 1.1.1.1 enable                               配置MP-BGP邻居

RR1和ASBR1建立IBGP邻居（RR1为反射器）

RR1

bgp 100

peer 3.3.3.3 as-number 100

peer 3.3.3.3 connect-interface LoopBack0

ipv4-family unicast

peer 3.3.3.3 enable

peer 3.3.3.3 reflect-client

ASBR1

bgp 100

peer 7.7.7.7 as-number 100

peer 7.7.7.7 connect-interface LoopBack0

ipv4-family unicast

peer 7.7.7.7 enable

ASBR1和ASBR2建立EBGP邻居

ASBR1

bgp 100

peer 100.0.34.4 as-number 200

ipv4-family unicast

peer 100.0.34.4 enable

ASBR2

bgp 200

peer 100.0.34.3 as-number 100

ipv4-family unicast

peer 100.0.34.3 enable

ASBR2和RR2建立IBGP邻居（RR2为反射器）

ASBR2

bgp 200

peer 8.8.8.8 as-number 200

peer 8.8.8.8 connect-interface LoopBack0

ipv4-family unicast

peer 8.8.8.8 enable

RR2

bgp 200

peer 4.4.4.4 as-number 200

peer 4.4.4.4 connect-interface LoopBack0

ipv4-family unicast

peer 4.4.4.4 enable

peer 4.4.4.4 reflect-client

RR2和PE2建立IBGP邻居和MP-IBGP邻居（RR2为反射器）

RR2

bgp 200

peer 6.6.6.6 as-number 200

peer 6.6.6.6 connect-interface LoopBack0

ipv4-family unicast

peer 6.6.6.6 enable

peer 6.6.6.6 reflect-client

ipv4-family vpnv4

undo policy vpn-target

peer 6.6.6.6 enable

PE2

bgp 200

peer 8.8.8.8 as-number 200

peer 8.8.8.8 connect-interface LoopBack0

ipv4-family unicast

undo synchronization

peer 8.8.8.8 enable

ipv4-family vpnv4

policy vpn-target

peer 8.8.8.8 enable

配置MPLS LDP

除了ASBR之间相连的接口、PE与CE相连接口，其余的接口都开启MPLS LDP

以PE1的配置为例（其余设备的配置同PE1）

全局开启MPLS LDP

mpls lsr-id 1.1.1.1

mpls

mpls ldp

接口下配置MPLS LDP

interface GigabitEthernet0/0/1

mpls

mpls ldp

配置RR之间的MP-BGP邻居

RR1和RR2建立MP-EBGP邻居

（RR1传给RR2、RR2传给RR1的Vpnv4路由要求更改下一跳-默认）

在ASBR上通过BGP邻居将RR1的路由传给RR2、将RR2的路由传给RR1

ASBR1

bgp 100

ipv4-family unicast

network 1.1.1.1 255.255.255.255

ASBR2

bgp 200

ipv4-family unicast

network 6.6.6.6 255.255.255.255

配置RR之间的MP-EBGP邻居

RR1

bgp 100

peer 8.8.8.8 as-number 200

peer 8.8.8.8 ebgp-max-hop 10

peer 8.8.8.8 connect-interface LoopBack0

ipv4-family unicast

undo peer 8.8.8.8 enable

ipv4-family vpnv4

undo policy vpn-target

peer 8.8.8.8 enable

peer 8.8.8.8 next-hop-invariable

RR2

bgp 200

peer 7.7.7.7 as-number 100

peer 7.7.7.7 ebgp-max-hop 10

peer 7.7.7.7 connect-interface LoopBack0

ipv4-family unicast

undo peer 7.7.7.7 enable

ipv4-family vpnv4

  undo policy vpn-target

peer 7.7.7.7 enable

peer 7.7.7.7 next-hop-invariable

此时双方虽然有对端的路由，但是无法建立邻居，此时需要在ASBR为RR手动分配标签

ASBR1为RR1分配标签给ASBR2；ASBR2为RR2分配标签给ASBR1

ASBR1

ip ip-prefix PE1-RR1 index 10 permit 7.7.7.7 32

route-policy PE1-RR1 permit node 10             此路由策略的目的为匹配7.7.7.7路由，为其分配标签

if-match ip-prefix PE1-RR1

apply mpls-label

bgp 100

ipv4-family unicast

peer 100.0.34.4 route-policy PE1-RR1 export 向100.0.34.4的邻居应用此路由策略

peer 100.0.34.4 label-route-capability            向100.0.34.4的邻居开启标签转发能力（可以向此邻居转发带标签的BGP路由）

ASBR2

ip ip-prefix PE2-RR2 index 20 permit 8.8.8.8 32

route-policy PE2-RR2 permit node 10

if-match ip-prefix PE2-RR2

apply mpls-label

bgp 200

ipv4-family unicast

peer 100.0.34.3 route-policy PE2-RR2 export

peer 100.0.34.3 label-route-capability

ASBR2获得RR1的标签后，重新分配标签分发给RR2

ASBR2

route-policy label permit node 10

if-match mpls-label

apply mpls-label

bgp 200

ipv4-family unicast

  peer 8.8.8.8 route-policy label export

peer 8.8.8.8 label-route-capability

RR2

bgp 200

ipv4-family unicast

peer 4.4.4.4 label-route-capability

ASBR1获得RR2的标签后，重新分配标签分发给RR1

ASBR1

route-policy label permit node 10

if-match mpls-label

apply mpls-label

bgp 200

ipv4-family unicast

  peer 7.7.7.7 route-policy label export

peer 7.7.7.7 label-route-capability

RR1

bgp 100

ipv4-family unicast

peer 3.3.3.3 label-route-capability

此时可以在RR上查看到关于对端RR的LSP标签路径，并且邻居建立RR邻居建立成功

此时RR将PE1上的Vpnv4路由传给PE2，PE2收到后，下一跳为8.8.8.8

此时CE2去往CE1的路由，封装RR2为CE1分配的私网标签，分装LDP为RR2生成的私网标签，然后就可以实现数据传输