配置思路：
- 先配置设备的互联地址，以及MPLS VPN区域内的lookback接口地址（用于建立BGP邻居关系），CE设备内部的地址（可为lookback地址），如需建立isis则使用接口地址
- AR1的g0/0/0创建两个子接口，AR2的g0/0/1也创建两个子接口
- 必须先建立lookback口和接口地址的isis（或者其他路由协议，需保证地址可达），作用为：
- 首先，建立LDP关系的LSR ID必须使用可达的IP地址，且最好为lookbacp地址
- 其次BGP关系的建立也最好为lookbacp地址，且路由要可达（详细原因可见BGP理论知识）
- R2上创建VPN实例，一个入一个出，配置RT值，R3和R4也创建VPN实例
- RT值有三种方案
- 第一种，AR3出入全为10：10，AR4出入全为20：20，此时AR2的入VPN为入的10：10和20：20，出VPN为出的10：10和20：20
- 第二种，AR3和AR4出都是10：10，入都是20：20，此时AR2为入VPN为 入10：10，出VPN为出20：20
- 第三种方案不推荐，AR2创建两个VPN实例，都设置出和入，这样的话有多少分公司就要设置多少个VPN实例，不推荐
- 注意：要保证AR3的出不能和AR4的入一致，要不然有可能不经过AR1直接转到AR4？（会这样吗？什么情况下会这样）
- MP-BGP配置，PE之间建立BGP邻居关系，AR2分别和AR3和AR4建立邻居关系
- PE和CE之间建立ospf，AR2中在入VPN实例由BGP引入到OSPF，在出VPN实例中由OSPF引入到BGP中（因为入VPN实例只进不出，出VPN实例只出不进）
- AR1的ospf进程号可以一样，AR2的ospf进程号必须不同，因为对AR1来说，是跟两个设备建立ospf邻居关系
- ospf必须宣告接口地址不然建立不起来，另外还需宣告业务地址（lookback地址）
- AR3和AR4双向引入
- 注：直连路由的下一跳为直连对端设备的IP地址，流量的走向的反方向就是路由传递的方向！！
- 在R2上取消ospf防环机制,DN置位和tag值
AR1:
[V200R003C00]
#
interface GigabitEthernet0/0/0
#
interface GigabitEthernet0/0/0.1
dot1q termination vid 10
ip address 10.1.5.2 255.255.255.0
ospf enable 1 area 0.0.0.0
arp broadcast enable
#
interface GigabitEthernet0/0/0.2
dot1q termination vid 20
ip address 10.1.6.1 255.255.255.0
ospf enable 1 area 0.0.0.0
arp broadcast enable
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
#
ospf 1
area 0.0.0.0
network 1.1.1.1 0.0.0.0
network 10.1.5.0 0.0.0.255
network 10.1.6.0 0.0.0.255
#
user-interface con 0
authentication-mode password
user-interface vty 0 4
user-interface vty 16 20
#
wlan ac
#
return
AR2:
[V200R003C00]
#
ip vpn-instance ex
ipv4-family
route-distinguisher 22:22
vpn-target 20:20 export-extcommunity
#
ip vpn-instance im
ipv4-family
route-distinguisher 12:12
vpn-target 10:10 import-extcommunity
#
mpls lsr-id 2.2.2.2
mpls
#
mpls ldp
#
#
isis 1
is-level level-2
network-entity 49.0000.0000.0010.00
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.1.3.1 255.255.255.0
isis enable 1
isis circuit-level level-2
mpls
mpls ldp
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/1.1
dot1q termination vid 10
ip binding vpn-instance im
ip address 10.1.5.1 255.255.255.0
ospf enable 1 area 0.0.0.0
arp broadcast enable
#
interface GigabitEthernet0/0/1.2
dot1q termination vid 20
ip binding vpn-instance ex
ip address 10.1.6.2 255.255.255.0
ospf enable 2 area 0.0.0.0
arp broadcast enable
#
interface GigabitEthernet0/0/2
ip address 10.1.2.2 255.255.255.0
isis enable 1
isis circuit-level level-2
mpls
mpls ldp
#
interface NULL0
#
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
isis enable 1
isis circuit-level level-2
#
bgp 100
peer 3.3.3.3 as-number 100
peer 3.3.3.3 connect-interface LoopBack0
peer 4.4.4.4 as-number 100
peer 4.4.4.4 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 3.3.3.3 enable
peer 4.4.4.4 enable
#
ipv4-family vpnv4
policy vpn-target
peer 3.3.3.3 enable
peer 4.4.4.4 enable
#
ipv4-family vpn-instance ex
import-route ospf 2
#
ipv4-family vpn-instance im
#
ospf 1 vpn-instance im
import-route bgp
dn-bit-set disable summary
dn-bit-set disable ase
area 0.0.0.0
network 10.1.5.0 0.0.0.255
#
ospf 2 vpn-instance ex
route-tag disable
area 0.0.0.0
network 10.1.6.0 0.0.0.255
#
wlan ac
#
return
AR3:
[V200R003C00]
#
ip vpn-instance a
ipv4-family
route-distinguisher 33:33
vpn-target 10:10 export-extcommunity
vpn-target 20:20 import-extcommunity
#
mpls lsr-id 3.3.3.3
mpls
#
mpls ldp
#
#
isis 1
is-level level-2
network-entity 49.0000.0000.0001.00
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.1.2.1 255.255.255.0
isis enable 1
isis circuit-level level-2
mpls
mpls ldp
#
interface GigabitEthernet0/0/1
ip binding vpn-instance a
ip address 10.1.1.2 255.255.255.0
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 3.3.3.3 255.255.255.255
isis enable 1
isis circuit-level level-2
#
bgp 100
peer 2.2.2.2 as-number 100
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
#
ipv4-family vpnv4
policy vpn-target
peer 2.2.2.2 enable
#
ipv4-family vpn-instance a
import-route ospf 1
#
ospf 1 vpn-instance a
import-route bgp
area 0.0.0.0
network 10.1.1.0 0.0.0.255
#
return
AR4:
[V200R003C00]
#
ip vpn-instance b
ipv4-family
route-distinguisher 14:14
vpn-target 10:10 export-extcommunity
vpn-target 20:20 import-extcommunity
#
mpls lsr-id 4.4.4.4
mpls
#
mpls ldp
#
#
isis 1
is-level level-2
network-entity 49.0000.0000.0011.00
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip binding vpn-instance b
ip address 10.1.4.1 255.255.255.0
#
interface GigabitEthernet0/0/1
ip address 10.1.3.2 255.255.255.0
isis enable 1
isis circuit-level level-2
mpls
mpls ldp
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 4.4.4.4 255.255.255.255
isis enable 1
isis circuit-level level-2
#
bgp 100
peer 2.2.2.2 as-number 100
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family unicast
undo synchronization
peer 2.2.2.2 enable
#
ipv4-family vpnv4
policy vpn-target
peer 2.2.2.2 enable
#
ipv4-family vpn-instance b
import-route ospf 1
#
ospf 1 vpn-instance b
import-route bgp
area 0.0.0.0
network 10.1.4.0 0.0.0.255
#
AR5:
[V200R003C00]
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.1.1.1 255.255.255.0
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
#
ospf 1
area 0.0.0.0
network 5.5.5.5 0.0.0.0
network 10.1.1.0 0.0.0.255
#
return
AR6:
[V200R003C00]
#
firewall zone Local
priority 15
#
interface GigabitEthernet0/0/0
ip address 10.1.4.2 255.255.255.0
#
interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/2
#
interface NULL0
#
interface LoopBack0
ip address 6.6.6.6 255.255.255.255
#
ospf 1
area 0.0.0.0
network 6.6.6.6 0.0.0.0
network 10.1.4.0 0.0.0.255
#
return
