重要的几点注意：
1、r2和r5上面不需要跑bgp，只开mpls ldp负责传递标签
2、r3和r4上面不需要跑vpnv4路由，只传标签就可以了。所以不要和自己as内的对端建立vpnv4路由，减轻压力。
3、r1和r6使用的是vpnv4路由，vpnv4路由的特点是它会自动进入mpls vpn隧道，所以r2和r5上面不存在mpls黑洞路由。
4、asbr之间只建立普通的ebgp邻居，且接口上只开mpls
5、2个asbr之间和各对内的ibgp都要开启发送标签能力，并用策略路由加上标签。
以下关键配置
R1：
ip vpn-instance a
ipv4-family
route-distinguisher 1:1
vpn-target 100:100 export-extcommunity
vpn-target 100:100 import-extcommunity
mpls lsr-id 1.1.1.1
mpls
mpls ldp
isis 1
network-entity 49.0000.0000.0000.0001.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.12.1 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/1
ip binding vpn-instance a
ip address 10.0.17.1 255.255.255.0
interface GigabitEthernet0/0/2
interface NULL0
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
isis enable 1
bgp 100
peer 3.3.3.3 as-number 100
peer 3.3.3.3 connect-interface LoopBack0
peer 6.6.6.6 as-number 200
peer 6.6.6.6 ebgp-max-hop 255
peer 6.6.6.6 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 3.3.3.3 enable
peer 3.3.3.3 label-route-capability
peer 6.6.6.6 enable
ipv4-family vpnv4
policy vpn-target
peer 6.6.6.6 enable
ipv4-family vpn-instance a
peer 10.0.17.7 as-number 60000
R2：
mpls lsr-id 2.2.2.2
mpls
mpls ldp
isis 1
network-entity 49.0000.0000.0002.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.12.2 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/1
ip address 10.0.23.2 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/2
interface NULL0
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
isis enable 1
R3
mpls lsr-id 3.3.3.3
mpls
mpls ldp
isis 1
network-entity 49.0000.0000.0003.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.23.3 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/1
ip address 10.0.34.3 255.255.255.0
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 1.1.1.1 as-number 100
peer 1.1.1.1 connect-interface LoopBack0
peer 10.0.34.4 as-number 200
ipv4-family unicast
undo synchronization
network 1.1.1.1 255.255.255.255
peer 1.1.1.1 enable
peer 1.1.1.1 route-policy labe1 export
peer 1.1.1.1 label-route-capability
peer 10.0.34.4 enable
peer 10.0.34.4 route-policy labe2 export
peer 10.0.34.4 label-route-capability
route-policy labe1 permit node 10
if-match mpls-label //只对过来带标签的数据加上标签，不带标签的数据则不加
apply mpls-label
route-policy labe2 permit node 10
apply mpls-label
R4
mpls lsr-id 4.4.4.4
mpls
mpls ldp
isis 1
network-entity 49.0001.0000.0000.0004.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.34.4 255.255.255.0
mpls
interface GigabitEthernet0/0/1
ip address 10.0.45.4 255.255.255.0
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 6.6.6.6 as-number 200
peer 6.6.6.6 connect-interface LoopBack0
peer 10.0.34.3 as-number 100
ipv4-family unicast
undo synchronization
network 6.6.6.6 255.255.255.255
peer 6.6.6.6 enable
peer 6.6.6.6 route-policy ibgp export
peer 6.6.6.6 label-route-capability
peer 10.0.34.3 enable
peer 10.0.34.3 route-policy asbr export
peer 10.0.34.3 label-route-capability
route-policy ibgp permit node 10
if-match mpls-label
apply mpls-label
route-policy asbr permit node 10
apply mpls-label
R5
mpls lsr-id 5.5.5.5
mpls
mpls ldp
isis 1
network-entity 49.0001.0000.0000.0005.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.45.5 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/1
ip address 10.0.56.5 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/2
interface NULL0
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
isis enable 1
R6：
ip vpn-instance a
ipv4-family
route-distinguisher 1:1
vpn-target 100:100 export-extcommunity
vpn-target 100:100 import-extcommunity
mpls lsr-id 6.6.6.6
mpls
mpls ldp
isis 1
network-entity 49.0001.0000.0000.0006.00
firewall zone Local
priority 15
interface GigabitEthernet0/0/0
ip address 10.0.56.6 255.255.255.0
isis enable 1
mpls
mpls ldp
interface GigabitEthernet0/0/1
ip binding vpn-instance a
ip address 10.0.68.6 255.255.255.0
interface GigabitEthernet0/0/2
interface NULL0
interface LoopBack0
ip address 6.6.6.6 255.255.255.255
isis enable 1
bgp 200
peer 1.1.1.1 as-number 100
peer 1.1.1.1 ebgp-max-hop 255
peer 1.1.1.1 connect-interface LoopBack0
peer 4.4.4.4 as-number 200
peer 4.4.4.4 connect-interface LoopBack0
ipv4-family unicast
undo synchronization
peer 1.1.1.1 enable
peer 4.4.4.4 enable
peer 4.4.4.4 label-route-capability
ipv4-family vpnv4
policy vpn-target
peer 1.1.1.1 enable
ipv4-family vpn-instance a
peer 10.0.68.8 as-number 60001