CCIE培训（EI方向）考试学习-MPLS解决BGP路由黑洞实验含拓扑

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CCIE培训MPLS实验

如图所示，R1属于Site-A， R2属于Site-B，R2/R3/R4/R5作为运营商

 根据拓扑配置设备IP地址；

 使用OSPF协议配置运营商内部的底层网络，进程号为“1”；

 R2-R5建立IBGP邻居，R1-R2、R5-R6建立EBGP邻居；

 在R1和R6上将Loopback0口网段宣告进BGP；

 在运营商网络内部启用MPLS，并观察实验现象。

Note：为了方便观察实验现象，你可以限制每台路由器所分发的标签范围

2 使用镜像

R1-R6：vIOS Version 15.8(3)M2

3 底层配置

3.1 配置运营商底层

R2：

R2(config)#interface Loopback0

R2(config-if)#ip address 2.2.2.2 255.255.255.255

R2(config-if)#exit

R2(config)#interface GigabitEthernet0/0

R2(config-if)#ip address 12.1.1.2 255.255.255.0

R2(config-if)#no shutdown

R2(config-if)#exit

R2(config)#interface GigabitEthernet0/1

R2(config-if)#ip address 23.1.1.2 255.255.255.0

R2(config-if)#no shutdown

R2(config-if)#exit

R2(config)#

R3：

R3(config)#interface Loopback0

R3(config-if)#ip address 3.3.3.3 255.255.255.255

R3(config-if)#exit

R3(config)#interface GigabitEthernet0/1

R3(config-if)#ip address 23.1.1.3 255.255.255.0

R3(config-if)#no shutdown

R3(config-if)#exit

R3(config)#interface GigabitEthernet0/0

R3(config-if)#ip address 34.1.1.3 255.255.255.0

R3(config-if)#no shutdown

R3(config-if)#exit

R3(config)#

R4：

R4(config)#interface Loopback0

R4(config-if)#ip address 4.4.4.4 255.255.255.255

R4(config-if)#exit

R4(config)#interface GigabitEthernet0/0

R4(config-if)#ip address 34.1.1.4 255.255.255.0

R4(config-if)#no shutdown

R4(config-if)#exit

R4(config)#interface GigabitEthernet0/1

R4(config-if)#ip address 45.1.1.4 255.255.255.0

R4(config-if)#no shutdown

R4(config-if)#exit

R4(config)#

R5：

R5(config)#interface Loopback0

R5(config-if)#ip address 5.5.5.5 255.255.255.255

R5(config-if)#exit

R5(config)#interface GigabitEthernet0/1

R5(config-if)#ip address 45.1.1.5 255.255.255.0

R5(config-if)#no shutdown

R5(config-if)#exit

R5(config)#interface GigabitEthernet0/0

R5(config-if)#ip address 56.1.1.5 255.255.255.0

R5(config-if)#no shutdown

R5(config-if)#exit

R5(config)#

CCIE培训MPLS实验

底层OSPF

R2：

R2(config)#router ospf 1

R2(config-router)#router-id 2.2.2.2

R2(config-router)#exit

R2(config)#interface Loopback0

R2(config-if)#ip ospf 1 area 0

R2(config-if)#exit

R2(config)#interface GigabitEthernet0/1

R2(config-if)#ip ospf 1 area 0

R2(config-if)#exit

R3：

R3(config)#router ospf 1

R3(config-router)#router-id 3.3.3.3

R3(config-router)#exit

R3(config)#interface Loopback0

R3(config-if)#ip ospf 1 area 0

R3(config-if)#exit

R3(config)#interface GigabitEthernet0/0

R3(config-if)#ip ospf 1 area 0

R3(config-if)#exit

R3(config)#interface GigabitEthernet0/1

R3(config-if)#ip ospf 1 area 0

R3(config-if)#exit

R4：

R4(config)#router ospf 1

R4(config-router)#router-id 4.4.4.4

R4(config-router)#exit

R4(config)#interface Loopback0

R4(config-if)#ip ospf 1 area 0

R4(config-if)#exit

R4(config)#interface GigabitEthernet0/0

R4(config-if)#ip ospf 1 area 0

R4(config-if)#exit

R4(config)#interface GigabitEthernet0/1

R4(config-if)#ip ospf 1 area 0

R4(config-if)#exit

R5：

R5(config)#router ospf 1

R5(config-router)#router-id 5.5.5.5

R5(config-router)#exit

R5(config)#interface Loopback0

R5(config-if)#ip ospf 1 area 0

R5(config-if)#exit

R5(config)#interface GigabitEthernet0/1

R5(config-if)#ip ospf 1 area 0

R5(config-if)#exit

3.2 配置Site-A&Site-B底层

R1：

R1(config)#interface GigabitEthernet0/0

R1(config-if)#ip address 12.1.1.1 255.255.255.0

R1(config-if)#no shutdown

R1(config-if)#exit

R1(config)#interface Loopback0

R1(config-if)#ip address 1.1.1.1 255.255.255.255

R1(config-if)#exit

R1(config)#

R6：

R6(config)#interface GigabitEthernet0/0

R6(config-if)#ip address 56.1.1.6 255.255.255.0

R6(config-if)#no shutdown

R6(config-if)#exit

R6(config)#interface Loopback0

R6(config-if)#ip address 6.6.6.6 255.255.255.255

R6(config-if)#exit

R6(config)#

3.3 配置BGP

R2：

R2(config)#router bgp 2345

R2(config-router)#bgp router-id 2.2.2.2

R2(config-router)#neighbor 5.5.5.5 remote-as 2345

R2(config-router)#neighbor 5.5.5.5 update-source Loopback0

R2(config-router)#neighbor 5.5.5.5 next-hop-self

R2(config-router)#neighbor 12.1.1.1 remote-as 100

R2(config-router)#exit

R2(config)#

R5：

R5(config)#router bgp 2345

R5(config-router)#bgp router-id 5.5.5.5

R5(config-router)#neighbor 2.2.2.2 remote-as 2345

R5(config-router)#neighbor 2.2.2.2 update-source Loopback0

R5(config-router)#neighbor 2.2.2.2 next-hop-self

R5(config-router)#neighbor 56.1.1.6 remote-as 600

R5(config-router)#exit

R5(config)#

R1：

R1(config)#router bgp 100

R1(config-router)#bgp router-id 1.1.1.1

R1(config-router)#neighbor 12.1.1.2 remote-as 2345

R1(config-router)#network 1.1.1.1 mask 255.255.255.255

R1(config-router)#exit

R1(config)#

R6：

R6(config)#router bgp 600

R6(config-router)#bgp router-id 6.6.6.6

R6(config-router)#neighbor 56.1.1.6 remote-as 2345

R6(config-router)#network 6.6.6.6 mask 255.255.255.255

R6(config-router)#exit

R6(config)#

4 观察现象

4.1 查看BGP表

R1：

R1#show ip bgp

BGP table version is 3, local router ID is 1.1.1.1

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 

              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 

              x best-external, a additional-path, c RIB-compressed, 

              t secondary path, 

Origin codes: i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path

 *>   1.1.1.1/32 0.0.0.0 0 32768 i

 *>   6.6.6.6/32 12.1.1.2 0 2345 600 i

R1#

R2：

R2#show ip bgp

BGP table version is 3, local router ID is 2.2.2.2

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 

              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 

              x best-external, a additional-path, c RIB-compressed, 

              t secondary path, 

Origin codes: i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path

 *>   1.1.1.1/32 12.1.1.1 0 0 100 i

 *>i  6.6.6.6/32 5.5.5.5 0    100 0 600 i

R2#

R5：

R5#show ip bgp

BGP table version is 3, local router ID is 5.5.5.5

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 

              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 

              x best-external, a additional-path, c RIB-compressed, 

              t secondary path, 

Origin codes: i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path

 *>i  1.1.1.1/32 2.2.2.2 0    100 0 100 i

 *>   6.6.6.6/32 56.1.1.6 0 0 600 i

R5#

R6：

R6#show ip bgp

BGP table version is 3, local router ID is 6.6.6.6

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 

              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 

              x best-external, a additional-path, c RIB-compressed, 

              t secondary path, 

Origin codes: i - IGP, e - EGP, ? - incomplete

RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path

 *>   1.1.1.1/32 56.1.1.5 0 2345 100 i

 *>   6.6.6.6/32 0.0.0.0 0 32768 i

R6#

4.2 测试可达性

R1：

R1#ping 6.6.6.6 source Loopback0

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 6.6.6.6, timeout is 2 seconds:

Packet sent with a source address of 1.1.1.1 

.....

Success rate is 0 percent (0/5)

R1#

R1无法使用Loopback0接口ping通6.6.6.6

4.3 查看路由表

R1：

R1#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 12.1.1.2 to network 0.0.0.0

      1.0.0.0/32 is subnetted, 1 subnets

C        1.1.1.1 is directly connected, Loopback0

      6.0.0.0/32 is subnetted, 1 subnets

B        6.6.6.6 [20/0] via 12.1.1.2, 00:10:52

      12.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        12.1.1.0/24 is directly connected, GigabitEthernet0/0

L        12.1.1.1/32 is directly connected, GigabitEthernet0/0

R1#

R2：

R2#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets

B        1.1.1.1 [20/0] via 12.1.1.1, 00:12:30

      2.0.0.0/32 is subnetted, 1 subnets

C        2.2.2.2 is directly connected, Loopback0

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/2] via 23.1.1.3, 01:36:01, GigabitEthernet0/1

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/3] via 23.1.1.3, 01:35:30, GigabitEthernet0/1

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/4] via 23.1.1.3, 01:35:06, GigabitEthernet0/1

      6.0.0.0/32 is subnetted, 1 subnets

B        6.6.6.6 [200/0] via 5.5.5.5, 00:11:29

      12.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        12.1.1.0/24 is directly connected, GigabitEthernet0/0

L        12.1.1.2/32 is directly connected, GigabitEthernet0/0

      23.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        23.1.1.0/24 is directly connected, GigabitEthernet0/1

L        23.1.1.2/32 is directly connected, GigabitEthernet0/1

      34.0.0.0/24 is subnetted, 1 subnets

O        34.1.1.0 [110/2] via 23.1.1.3, 01:35:40, GigabitEthernet0/1

      45.0.0.0/24 is subnetted, 1 subnets

O        45.1.1.0 [110/3] via 23.1.1.3, 01:35:16, GigabitEthernet0/1

R2#

R3：

R3#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/2] via 23.1.1.2, 01:37:15, GigabitEthernet0/1

      3.0.0.0/32 is subnetted, 1 subnets

C        3.3.3.3 is directly connected, Loopback0

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/2] via 34.1.1.4, 01:36:50, GigabitEthernet0/0

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/3] via 34.1.1.4, 01:36:20, GigabitEthernet0/0

      23.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        23.1.1.0/24 is directly connected, GigabitEthernet0/1

L        23.1.1.3/32 is directly connected, GigabitEthernet0/1

      34.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        34.1.1.0/24 is directly connected, GigabitEthernet0/0

L        34.1.1.3/32 is directly connected, GigabitEthernet0/0

      45.0.0.0/24 is subnetted, 1 subnets

O        45.1.1.0 [110/2] via 34.1.1.4, 01:36:30, GigabitEthernet0/0

R3#

R4：

R4#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/3] via 34.1.1.3, 01:37:18, GigabitEthernet0/0

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/2] via 34.1.1.3, 01:37:18, GigabitEthernet0/0

      4.0.0.0/32 is subnetted, 1 subnets

C        4.4.4.4 is directly connected, Loopback0

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/2] via 45.1.1.5, 01:36:53, GigabitEthernet0/1

      23.0.0.0/24 is subnetted, 1 subnets

O        23.1.1.0 [110/2] via 34.1.1.3, 01:37:18, GigabitEthernet0/0

      34.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        34.1.1.0/24 is directly connected, GigabitEthernet0/0

L        34.1.1.4/32 is directly connected, GigabitEthernet0/0

      45.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        45.1.1.0/24 is directly connected, GigabitEthernet0/1

L        45.1.1.4/32 is directly connected, GigabitEthernet0/1

R4#

R5：

R5#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets

B        1.1.1.1 [200/0] via 2.2.2.2, 00:14:28

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/4] via 45.1.1.4, 01:37:13, GigabitEthernet0/1

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/3] via 45.1.1.4, 01:37:13, GigabitEthernet0/1

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/2] via 45.1.1.4, 01:37:13, GigabitEthernet0/1

      5.0.0.0/32 is subnetted, 1 subnets

C        5.5.5.5 is directly connected, Loopback0

      6.0.0.0/32 is subnetted, 1 subnets

B        6.6.6.6 [20/0] via 56.1.1.6, 00:13:27

      23.0.0.0/24 is subnetted, 1 subnets

O        23.1.1.0 [110/3] via 45.1.1.4, 01:37:13, GigabitEthernet0/1

      34.0.0.0/24 is subnetted, 1 subnets

O        34.1.1.0 [110/2] via 45.1.1.4, 01:37:13, GigabitEthernet0/1

      45.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        45.1.1.0/24 is directly connected, GigabitEthernet0/1

L        45.1.1.5/32 is directly connected, GigabitEthernet0/1

      56.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        56.1.1.0/24 is directly connected, GigabitEthernet0/0

L        56.1.1.5/32 is directly connected, GigabitEthernet0/0

R5#

R6：

R6#show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 56.1.1.5 to network 0.0.0.0

      1.0.0.0/32 is subnetted, 1 subnets

B        1.1.1.1 [20/0] via 56.1.1.5, 00:14:30

      6.0.0.0/32 is subnetted, 1 subnets

C        6.6.6.6 is directly connected, Loopback0

      56.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        56.1.1.0/24 is directly connected, GigabitEthernet0/0

L        56.1.1.6/32 is directly connected, GigabitEthernet0/0

R6#

从上述输出可见：R3和R4是路由黑洞，没有1.1.1.1/32和6.6.6.6/32网段的路由

5 MPLS配置

5.1 配置MPLS

R2：

R2(config)#mpls label protocol ldp //配置标签分发协议为LDP

R2(config)#mpls ldp router-id Loopback0 //配置LDP的router-id

R2(config)#mpls label range 2000 2999 //配置标签的分发范围

R2(config)#interface GigabitEthernet0/1

R2(config-if)#mpls ip //接口下启用MPLS

R2(config-if)#exit

R2(config)#

R3：

R3(config)#mpls label protocol ldp //配置标签分发协议为LDP

R3(config)#mpls ldp router-id Loopback0 //配置LDP的router-id

R3(config)#mpls label range 3000 3999 //配置标签的分发范围

R3(config)#interface GigabitEthernet0/0

R3(config-if)#mpls ip //接口下启用MPLS

R3 (config-if)#exit

R3(config)#interface GigabitEthernet0/1

R3(config-if)#mpls ip //接口下启用MPLS

R3(config-if)#exit

R3(config)#

R4：

R4(config)#mpls label protocol ldp //配置标签分发协议为LDP

R4(config)#mpls ldp router-id Loopback0 //配置LDP的router-id

R4(config)#mpls label range 4000 4999 //配置标签的分发范围

R4(config)#interface GigabitEthernet0/0

R4(config-if)#mpls ip //接口下启用MPLS

R4 (config-if)#exit

R4(config)#interface GigabitEthernet0/1

R4(config-if)#mpls ip //接口下启用MPLS

R4(config-if)#exit

R4(config)#

R5：

R5(config)#mpls label protocol ldp //配置标签分发协议为LDP

R5(config)#mpls ldp router-id Loopback0 //配置LDP的router-id

R5(config)#mpls label range 5000 5999 //配置标签的分发范围

R5(config)#interface GigabitEthernet0/1

R5(config-if)#mpls ip //接口下启用MPLS

R5(config-if)#exit

R5(config)#

6 现象分析

6.1 相关show命令

Router#show mpls ldp neighbor //查看LDP邻居

Router#show ip route //查看RIB

Router#show ip cef //查看FIB

Router#show mpls ldp bindings //查看LIB

Router#show mpls forwarding-table //查看LFIB

6.2 查看RIB

R2：

R2# show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets

B        1.1.1.1 [20/0] via 12.1.1.1, 00:29:19

      2.0.0.0/32 is subnetted, 1 subnets

C        2.2.2.2 is directly connected, Loopback0

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/2] via 23.1.1.3, 01:52:50, GigabitEthernet0/1

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/3] via 23.1.1.3, 01:52:19, GigabitEthernet0/1

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/4] via 23.1.1.3, 01:51:55, GigabitEthernet0/1

      6.0.0.0/32 is subnetted, 1 subnets

B        6.6.6.6 [200/0] via 5.5.5.5, 00:28:18

      12.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        12.1.1.0/24 is directly connected, GigabitEthernet0/0

L        12.1.1.2/32 is directly connected, GigabitEthernet0/0

      23.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        23.1.1.0/24 is directly connected, GigabitEthernet0/1

L        23.1.1.2/32 is directly connected, GigabitEthernet0/1

      34.0.0.0/24 is subnetted, 1 subnets

O        34.1.1.0 [110/2] via 23.1.1.3, 01:52:29, GigabitEthernet0/1

      45.0.0.0/24 is subnetted, 1 subnets

O        45.1.1.0 [110/3] via 23.1.1.3, 01:52:05, GigabitEthernet0/1

R2#

R3：

R3# show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/2] via 23.1.1.2, 01:54:30, GigabitEthernet0/1

      3.0.0.0/32 is subnetted, 1 subnets

C        3.3.3.3 is directly connected, Loopback0

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/2] via 34.1.1.4, 01:54:05, GigabitEthernet0/0

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/3] via 34.1.1.4, 01:53:35, GigabitEthernet0/0

      23.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        23.1.1.0/24 is directly connected, GigabitEthernet0/1

L        23.1.1.3/32 is directly connected, GigabitEthernet0/1

      34.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        34.1.1.0/24 is directly connected, GigabitEthernet0/0

L        34.1.1.3/32 is directly connected, GigabitEthernet0/0

      45.0.0.0/24 is subnetted, 1 subnets

O        45.1.1.0 [110/2] via 34.1.1.4, 01:53:45, GigabitEthernet0/0

R3#

R4：

R4# show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/3] via 34.1.1.3, 01:55:10, GigabitEthernet0/0

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/2] via 34.1.1.3, 01:55:10, GigabitEthernet0/0

      4.0.0.0/32 is subnetted, 1 subnets

C        4.4.4.4 is directly connected, Loopback0

      5.0.0.0/32 is subnetted, 1 subnets

O        5.5.5.5 [110/2] via 45.1.1.5, 01:54:45, GigabitEthernet0/1

      23.0.0.0/24 is subnetted, 1 subnets

O        23.1.1.0 [110/2] via 34.1.1.3, 01:55:10, GigabitEthernet0/0

      34.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        34.1.1.0/24 is directly connected, GigabitEthernet0/0

L        34.1.1.4/32 is directly connected, GigabitEthernet0/0

      45.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        45.1.1.0/24 is directly connected, GigabitEthernet0/1

L        45.1.1.4/32 is directly connected, GigabitEthernet0/1

R4#

R5：

R5# show ip route

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       a - application route

       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets

B        1.1.1.1 [200/0] via 2.2.2.2, 00:32:35

      2.0.0.0/32 is subnetted, 1 subnets

O        2.2.2.2 [110/4] via 45.1.1.4, 01:55:20, GigabitEthernet0/1

      3.0.0.0/32 is subnetted, 1 subnets

O        3.3.3.3 [110/3] via 45.1.1.4, 01:55:20, GigabitEthernet0/1

      4.0.0.0/32 is subnetted, 1 subnets

O        4.4.4.4 [110/2] via 45.1.1.4, 01:55:20, GigabitEthernet0/1

      5.0.0.0/32 is subnetted, 1 subnets

C        5.5.5.5 is directly connected, Loopback0

      6.0.0.0/32 is subnetted, 1 subnets

B        6.6.6.6 [20/0] via 56.1.1.6, 00:31:34

      23.0.0.0/24 is subnetted, 1 subnets

O        23.1.1.0 [110/3] via 45.1.1.4, 01:55:20, GigabitEthernet0/1

      34.0.0.0/24 is subnetted, 1 subnets

O        34.1.1.0 [110/2] via 45.1.1.4, 01:55:20, GigabitEthernet0/1

      45.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        45.1.1.0/24 is directly connected, GigabitEthernet0/1

L        45.1.1.5/32 is directly connected, GigabitEthernet0/1

      56.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C        56.1.1.0/24 is directly connected, GigabitEthernet0/0

L        56.1.1.5/32 is directly connected, GigabitEthernet0/0

R5#

从上述输出可见：R3和R4依然是路由黑洞，没有1.1.1.1/32和6.6.6.6/32网段的路由。

6.3 查看FIB

R2：

R2# show ip cef

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32           receive              

1.1.1.1/32           12.1.1.1             GigabitEthernet0/0

2.2.2.2/32           receive              Loopback0

3.3.3.3/32           23.1.1.3             GigabitEthernet0/1

4.4.4.4/32           23.1.1.3             GigabitEthernet0/1

5.5.5.5/32           23.1.1.3             GigabitEthernet0/1

6.6.6.6/32           23.1.1.3             GigabitEthernet0/1

12.1.1.0/24          attached             GigabitEthernet0/0

12.1.1.0/32          receive              GigabitEthernet0/0

12.1.1.1/32          attached             GigabitEthernet0/0

12.1.1.2/32          receive              GigabitEthernet0/0

12.1.1.255/32        receive              GigabitEthernet0/0

23.1.1.0/24          attached             GigabitEthernet0/1

23.1.1.0/32          receive              GigabitEthernet0/1

23.1.1.2/32          receive              GigabitEthernet0/1

23.1.1.3/32          attached             GigabitEthernet0/1

23.1.1.255/32        receive              GigabitEthernet0/1

34.1.1.0/24          23.1.1.3             GigabitEthernet0/1

45.1.1.0/24          23.1.1.3             GigabitEthernet0/1

127.0.0.0/8          drop

224.0.0.0/4          drop

224.0.0.0/24         receive              

240.0.0.0/4          drop

255.255.255.255/32   receive              

R2# show ip cef 6.6.6.6

6.6.6.6/32

  nexthop 23.1.1.3 GigabitEthernet0/1 label 3002-(local:2002)

R2#

R3：

R3# show ip cef

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32           receive              

2.2.2.2/32           23.1.1.2             GigabitEthernet0/1

3.3.3.3/32           receive              Loopback0

4.4.4.4/32           34.1.1.4             GigabitEthernet0/0

5.5.5.5/32           34.1.1.4             GigabitEthernet0/0

23.1.1.0/24          attached             GigabitEthernet0/1

23.1.1.0/32          receive              GigabitEthernet0/1

23.1.1.2/32          attached             GigabitEthernet0/1

23.1.1.3/32          receive              GigabitEthernet0/1

23.1.1.255/32        receive              GigabitEthernet0/1

34.1.1.0/24          attached             GigabitEthernet0/0

34.1.1.0/32          receive              GigabitEthernet0/0

34.1.1.3/32          receive              GigabitEthernet0/0

34.1.1.4/32          attached             GigabitEthernet0/0

34.1.1.255/32        receive              GigabitEthernet0/0

45.1.1.0/24          34.1.1.4             GigabitEthernet0/0

127.0.0.0/8          drop

224.0.0.0/4          drop

224.0.0.0/24         receive              

240.0.0.0/4          drop

255.255.255.255/32   receive              

R3#

R4：

R4# show ip cef

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32           receive              

2.2.2.2/32           34.1.1.3             GigabitEthernet0/0

3.3.3.3/32           34.1.1.3             GigabitEthernet0/0

4.4.4.4/32           receive              Loopback0

5.5.5.5/32           45.1.1.5             GigabitEthernet0/1

23.1.1.0/24          34.1.1.3             GigabitEthernet0/0

34.1.1.0/24          attached             GigabitEthernet0/0

34.1.1.0/32          receive              GigabitEthernet0/0

34.1.1.3/32          attached             GigabitEthernet0/0

34.1.1.4/32          receive              GigabitEthernet0/0

34.1.1.255/32        receive              GigabitEthernet0/0

45.1.1.0/24          attached             GigabitEthernet0/1

45.1.1.0/32          receive              GigabitEthernet0/1

45.1.1.4/32          receive              GigabitEthernet0/1

45.1.1.5/32          attached             GigabitEthernet0/1

45.1.1.255/32        receive              GigabitEthernet0/1

127.0.0.0/8          drop

224.0.0.0/4          drop

224.0.0.0/24         receive              

240.0.0.0/4          drop

255.255.255.255/32   receive              

R4#

R5：

R5# show ip cef

Prefix               Next Hop             Interface

0.0.0.0/0            no route

0.0.0.0/8            drop

0.0.0.0/32           receive              

1.1.1.1/32           45.1.1.4             GigabitEthernet0/1

2.2.2.2/32           45.1.1.4             GigabitEthernet0/1

3.3.3.3/32           45.1.1.4             GigabitEthernet0/1

4.4.4.4/32           45.1.1.4             GigabitEthernet0/1

5.5.5.5/32           receive              Loopback0

6.6.6.6/32           56.1.1.6             GigabitEthernet0/0

23.1.1.0/24          45.1.1.4             GigabitEthernet0/1

34.1.1.0/24          45.1.1.4             GigabitEthernet0/1

45.1.1.0/24          attached             GigabitEthernet0/1

45.1.1.0/32          receive              GigabitEthernet0/1

45.1.1.4/32          attached             GigabitEthernet0/1

45.1.1.5/32          receive              GigabitEthernet0/1

45.1.1.255/32        receive              GigabitEthernet0/1

56.1.1.0/24          attached             GigabitEthernet0/0

56.1.1.0/32          receive              GigabitEthernet0/0

56.1.1.5/32          receive              GigabitEthernet0/0

56.1.1.6/32          attached             GigabitEthernet0/0

56.1.1.255/32        receive              GigabitEthernet0/0

127.0.0.0/8          drop

224.0.0.0/4          drop

224.0.0.0/24         receive              

240.0.0.0/4          drop

255.255.255.255/32   receive              

R5#   

R5# show ip cef 1.1.1.1

1.1.1.1/32

  nexthop 45.1.1.4 GigabitEthernet0/1 label 4000-(local:5000)

R5#

从上述输出可见：R3和R4虽然是路由黑洞，没有1.1.1.1/32和6.6.6.6/32网段的路由，但是目的地址1.1.1.1的数据包在R2-R3链路上是通过标签转发的，目的地址6.6.6.6的数据包在R5-R4上亦是如此。

6.4 R1-R2之间的链路

R1查看FIB发包：

R2#show ip cef

6.6.6.6/32

  nexthop 12.1.1.2 GigabitEthernet0/0

R2#

R1发出的是一个IP包，下一跳R2。

6.5 R2-R3之间的链路

R2：

R2#show mpls ldp bindings

  lib entry: 2.2.2.2/32, rev 2

        local binding:  label: imp-null

        remote binding: lsr: 3.3.3.3:0, label: 3000

  lib entry: 3.3.3.3/32, rev 4

        local binding:  label: 2000

        remote binding: lsr: 3.3.3.3:0, label: imp-null

  lib entry: 4.4.4.4/32, rev 6

        local binding:  label: 2001

        remote binding: lsr: 3.3.3.3:0, label: 3001

  lib entry: 5.5.5.5/32, rev 8

        local binding:  label: 2002

        remote binding: lsr: 3.3.3.3:0, label: 3002

  lib entry: 12.1.1.0/24, rev 10

        local binding:  label: imp-null

  lib entry: 23.1.1.0/24, rev 12

        local binding:  label: imp-null

        remote binding: lsr: 3.3.3.3:0, label: imp-null

  lib entry: 34.1.1.0/24, rev 14

        local binding:  label: 2003

        remote binding: lsr: 3.3.3.3:0, label: imp-null

  lib entry: 45.1.1.0/24, rev 16

        local binding:  label: 2004

        remote binding: lsr: 3.3.3.3:0, label: 3003

R2#  

CCIE培训MPLS实验

从上述输出可以看出：R2为5.5.5.5/32这条路由分配的标签是2002，下一跳R3为5.5.5.5/32这条路由分配的标签是3002，而且R2并未给BGP路由6.6.6.6/32分配标签。

R2收到的是IP包，所以查询FIB：

R2# show ip cef 6.6.6.6

6.6.6.6/32

  nexthop 23.1.1.3 GigabitEthernet0/1 label 3002-(local:2002)

R2#

从上述输出得知：虽然R2并未给BGP路由6.6.6.6/32分配标签，但是R2会为被6.6.6.6/32这条路由所匹配的数据包打上下一跳5.5.5.5所对应的出标签3002

6.6 R3-R4之间的链路

R3收到的是标签包，标签3002，所以查询LFIB：

R3# show mpls forwarding-table

Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    

Label      Label      or Tunnel Id     Switched      interface              

3000       Pop Label  2.2.2.2/32       5269          Gi0/1      23.1.1.2    

3001       Pop Label  4.4.4.4/32       0             Gi0/0      34.1.1.4    

3002       4002       5.5.5.5/32       5659          Gi0/0      34.1.1.4    

3003       Pop Label  45.1.1.0/24      0             Gi0/0      34.1.1.4    

R3#

通过LFIB得知：R3将收到数据包中的标签3002替换成4002，下一跳R4。

6.7 R4-R5之间的链路

R4收到的是标签包，标签4002，所以查询LFIB：

R4# show mpls forwarding-table

R4#sh mpls forwarding-table 

Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop    

Label      Label      or Tunnel Id     Switched      interface              

4000       3000       2.2.2.2/32       6404          Gi0/0      34.1.1.3    

4001       Pop Label  3.3.3.3/32       0             Gi0/0      34.1.1.3    

4002       Pop Label  5.5.5.5/32       6031          Gi0/1      45.1.1.5    

4003       Pop Label  23.1.1.0/24      0             Gi0/0      34.1.1.3    

R4#

通过LFIB得知：R4将收到数据包中的标签4002替换成隐含空标签（次末跳弹出），下一跳R5，由于收到的数据包只有单层标签，所以交给R5的数据包将是一个IP包。

6.8 R5-R6之间的链路

R5收到的是IP包，所以查询FIB：

R5# show ip cef 6.6.6.6

6.6.6.6/32

  nexthop 56.1.1.6 GigabitEthernet0/0

R5#

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