全网超详细MPLS Option C2方案实验完整介绍（RR场景，EBGP）

1.实验拓扑以及介绍：

 这是MPLS VPN Option C2方案，不同于其他方案：

  a.RR之间直接建立BGP VPNV4邻居（传递VPNV4路由）

  b.ASBR之间建立EBGP邻居，将BGP路由直接import底层IGP，使用IGP来建立标签

  c.RR和ASBR之间无需建立BGP VPNV4邻居和IPv4邻居

2.基本配置（基本每一步的配置后面都有对应）

 a.MPLS Domain基本配置（IP地址，IGP协议，MPLS LDP）

MPLS Domain 1：

AR1：
#
mpls lsr-id 1.1.1.1
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0001.00
#
interface GigabitEthernet0/0/0
ip address 10.1.12.1 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 1.1.1.1 255.255.255.255
isis enable 1

AR2：
#
mpls lsr-id 2.2.2.2
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0002.00
#
interface GigabitEthernet0/0/0
ip address 10.1.12.2 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface GigabitEthernet0/0/1
ip address 10.1.23.2 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
isis enable 1

AR3：
#
mpls lsr-id 3.3.3.3
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0003.00
#
interface GigabitEthernet0/0/0
ip address 10.1.23.3 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 3.3.3.3 255.255.255.255
isis enable 1

MPLS Domain 2：

AR4：
#
mpls lsr-id 4.4.4.4
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0004.00
#
interface GigabitEthernet0/0/0
ip address 10.1.45.4 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 4.4.4.4 255.255.255.255
isis enable 1

AR5：
#
mpls lsr-id 5.5.5.5
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0005.00
#
interface GigabitEthernet0/0/0
ip address 10.1.45.5 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface GigabitEthernet0/0/1
ip address 10.1.56.5 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
isis enable 1

AR6：
#
mpls lsr-id 6.6.6.6
mpls
#
mpls ldp
#
isis 1
is-level level-2
cost-style wide
network-entity 10.0001.0000.0000.0006.00
#
interface GigabitEthernet0/0/0
ip address 10.1.56.6 255.255.255.0
isis enable 1
mpls
mpls ldp
#
interface LoopBack0
ip address 6.6.6.6 255.255.255.255
isis enable 1

 b.Site的CE和PE建立EBGP邻居

AR1：
#
ip vpn-instance a
ipv4-family
route-distinguisher 1:1
vpn-target 1:100 export-extcommunity
vpn-target 1:100 import-extcommunity
#
interface GigabitEthernet0/0/1
ip binding vpn-instance a
ip address 10.1.17.1 255.255.255.0
#
bgp 200
router-id 1.1.1.1
#
ipv4-family vpn-instance a
peer 10.1.17.7 as-number 100
#

AR7：
#
interface LoopBack0
ip address 7.7.7.7 255.255.255.255
isis enable 1
#
interface GigabitEthernet0/0/0
ip address 10.1.17.7 255.255.255.0
#
bgp 100
router-id 7.7.7.7
peer 10.1.17.1 as-number 200
#
ipv4-family unicast
undo synchronization
network 7.7.7.7 255.255.255.255
network 8.8.8.8 255.255.255.255
peer 10.1.17.1 enable
#

AR6:
#
ip vpn-instance a
ipv4-family
route-distinguisher 1:2
vpn-target 1:100 export-extcommunity
vpn-target 1:100 import-extcommunity
#
interface GigabitEthernet0/0/1
ip binding vpn-instance a
ip address 10.1.68.6 255.255.255.0
#
bgp 300
router-id 6.6.6.6
#
ipv4-family vpn-instance a
peer 10.1.68.8 as-number 400
#

AR8:
#
interface LoopBack0
ip address 8.8.8.8 255.255.255.255
isis enable 1
#
interface GigabitEthernet0/0/0
ip address 10.1.68.8 255.255.255.0
#
bgp 400
router-id 8.8.8.8
peer 10.1.68.6 as-number 300
#
ipv4-family unicast
undo synchronization
network 8.8.8.8 255.255.255.255
peer 10.1.68.6 enable
#

 c.Site内建立BGP VPNV4 邻居

MPLS Domain 1：
AR1：
#
bgp 200
router-id 1.1.1.1
peer 2.2.2.2 as-number 200
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family vpnv4
policy vpn-target
peer 2.2.2.2 enable
#

AR2：
#
bgp 200
router-id 2.2.2.2
peer 1.1.1.1 as-number 200
peer 1.1.1.1 connect-interface LoopBack0
#
ipv4-family vpnv4
undo policy vpn-target
peer 1.1.1.1 enable
#

MPLS Domain 2：
AR5：
bgp 300
router-id 5.5.5.5
peer 6.6.6.6 as-number 300
peer 6.6.6.6 connect-interface LoopBack0
#
ipv4-family vpnv4
undo policy vpn-target
peer 6.6.6.6 enable
#

AR6：
#
bgp 300
router-id 6.6.6.6
peer 5.5.5.5 as-number 300
peer 5.5.5.5 connect-interface LoopBack0
#
ipv4-family vpnv4
policy vpn-target
peer 5.5.5.5 enable
#

 d.ASBR之间建立EBGP邻居

AR3：
#
interface GigabitEthernet0/0/1
ip address 10.1.34.3 255.255.255.0
#
bgp 200
peer 10.1.34.4 as-number 300
#
ipv4-family unicast
undo synchronization
network 1.1.1.1 255.255.255.255
network 2.2.2.2 255.255.255.255
peer 10.1.34.4 enable
#

AR4:
#
interface GigabitEthernet0/0/1
ip address 10.1.34.4 255.255.255.0
#
bgp 300
peer 10.1.34.3 as-number 200
#
ipv4-family unicast
undo synchronization
network 5.5.5.5 255.255.255.255
network 6.6.6.6 255.255.255.255
peer 10.1.34.3 enable
#

 e.ASBR策略配置标签和IGP引入路由生成标签

AR3:
#
interface GigabitEthernet0/0/1
ip address 10.1.34.3 255.255.255.0
mpls
#
isis 1
import-route bgp
#
ip ip-prefix asbr permit 1.1.1.1 32
ip ip-prefix asbr permit 2.2.2.2 32
#
route-policy asbr permit node 10
if-match ip-prefix 1
apply mpls-label
#
route-policy asbr permit node 20
#
bgp 200
peer 10.1.34.4 route-policy asbr export
peer 10.1.34.4 label-route-capability
#
mpls
lsp-trigger bgp-label-route
#

AR4:
#
interface GigabitEthernet0/0/1
ip address 10.1.34.4 255.255.255.0
mpls
#
isis 1
import-route bgp
#
ip ip-prefix asbr permit 5.5.5.5 32
ip ip-prefix asbr permit 6.6.6.6 32
#
route-policy asbr permit node 10
if-match ip-prefix 1
apply mpls-label
#
route-policy asbr permit node 20
#
bgp 300
peer 10.1.34.3 route-policy asbr export
peer 10.1.34.3 label-route-capability
#
mpls
lsp-trigger bgp-label-route
#

 f.RR之间建立BGP VPNV4邻居

AR2：
#
bgp 200
peer 5.5.5.5 as-number 300
peer 5.5.5.5 ebgp-max-hop 10
peer 5.5.5.5 connect-interface LoopBack0
#
ipv4-family unicast
undo peer 5.5.5.5 enable
#
ipv4-family vpnv4
undo policy vpn-target
peer 1.1.1.1 enable
peer 5.5.5.5 enable
peer 1.1.1.1 next-hop-invariable
peer 5.5.5.5 next-hop-invariable
#

AR5:
#
bgp 300
peer 2.2.2.2 as-number 200
peer 2.2.2.2 ebgp-max-hop 10
peer 2.2.2.2 connect-interface LoopBack0
#
ipv4-family unicast
undo peer 2.2.2.2 enable
#
ipv4-family vpnv4
undo policy vpn-target
peer 2.2.2.2 enable
peer 6.6.6.6 enable
peer 2.2.2.2 next-hop-invariable
peer 6.6.6.6 next-hop-invariable
#

3.结果验证

 a.isis邻居的建立

 b.MPLS LSP建立

c.Site的CE和PE之间的EBGP邻居建立：

d.MPLS Domain 内建立VPNV4邻居：

e.ASBR之间建立EBGP邻居：

f.RR之间VPNV4邻居建立：

g.是否可以ping通：

4.总结：

 a.为什么RR和ASBR之间不需要建立BGP任何邻居：

  首先不在依赖BGP IPv4邻居传递RR和PE设备的Loopback路由，再一个就是不需要传递VPNV4路由（并且避免不必要的标签产生）

 b.报文封装过程（参照下面的图）

全程只需要封装两层标签不在需要多层标签