跨域*** 組網實例-OptionC
組網需求
R1 和R6 屬於同一個***。R1 通過AS100 的R2 接入，R6 通過AS200 的R5 接入。採用OptionC 方式實現跨域的BGP/MPLS ***，即，採用PE 間通過Multi-hop MP-EBGP 發佈標籤***-IPv4 路由方式管理*** 路由。
配置思路大致如此：
1、先做通路由。在同一個AS內，先通過運行IGP做通AS內部路由，再在各PE路由器上運行BGP，宣告通過IGP學到的路由和直連路由。做完以後，可以在PE1（本實例中的R2）上PING通PE2（本實例中的R5）的L0接口和外部接口（F1/0）。
2、配置在各PE之間能夠交換帶標籤的IPV4路由。PE1（R2）與ASBR-PE1（R3）、PE2（R5）與ASBR-PE2（R4）、ASBR-PE1與ASBR-PE2
3、ASBR-PE在向本AS內的PE發佈路由時，將下一跳改爲自己
4、在ASBR-PE 上配置路由策略：對於從本AS 內的PE 接收的路由，在向對端AS的ASBR 發佈時，分配MPLS 標籤；對於向本AS 內的PE 發佈的路由，如果是帶標籤的IPv4 路由，爲其分配新的MPLS 標籤。
5、在PE與PE之間（R2與R5）建立鄰居關係，直接發佈***V4路由。所以在ASBR-PE上要有能夠支持帶標籤的IPV4路由的能力。（別忘了關閉默認的標籤過濾功能）。
r1#show run
!
hostname r1 #用戶CE設備，和ISP的PE設備相連
!
no ip domain lookup
!
ip cef
!
interface Loopback0
ip address 10.1.1.1 255.255.255.0 #模擬內網網段
!
interface FastEthernet0/0 # 內網出口接口，和ISP的PE相連
ip address 1.1.1.1 255.255.255.0
duplex half
!
router bgp 1000 #在CE上運行BGP，和相鄰的PE設備
no synchronization 建立EBGP鄰居
bgp log-neighbor-changes
redistribute connected #宣告直連網段
neighbor 1.1.1.2 remote-as 100 #和相鄰的PE設備建立EBGP鄰居
no auto-summary
!
ip classless
end
r2#show run
hostname r2 #PE設備，是ISP和用戶相連的設備
!
no ip domain lookup
!
ip vrf *** #創建一個VRF（***路由轉發），華爲稱作
rd 100:1 # ***實例，RD（路由標識符）
route-target export 100:1 #路由目標，用於路由過濾
route-target import 100:1
!
ip cef
!
interface Loopback0
ip address 20.1.1.1 255.255.255.255 #注意子網掩碼爲4個255，防止路
! #由被聚合，LSP不能正確處理內層標籤
interface FastEthernet0/0 #在此接口上綁定VRF
ip vrf forwarding *** #先做這一步，再配置IP地址
ip address 1.1.1.2 255.255.255.0
duplex half
!
interface FastEthernet1/0
ip address 2.1.1.1 255.255.255.0
duplex half
tag-switching ip #配置MPLS能力
!
router ospf 1 #運行OSPF 路由協議
log-adjacency-changes
network 2.1.1.1 0.0.0.0 area 0 #宣告
network 20.1.1.1 0.0.0.0 area 0
!
router bgp 100 #運行BGP路由協議，AS號爲100
bgp log-neighbor-changes
neighbor 30.1.1.1 remote-as 100 #和ASBR PE路由器建立鄰居關係
neighbor 30.1.1.1 update-source Loopback0
neighbor 50.1.1.1 remote-as 200 #和另一個AS中的PE建產鄰居關係
neighbor 50.1.1.1 ebgp-multihop 10 #允許最大跳數爲10跳
neighbor 50.1.1.1 update-source Loopback0
!
address-family ipv4
redistribute connected #引入直連路由
neighbor 30.1.1.1 activate #激活鄰居（默認）
neighbor 30.1.1.1 send-label #配置相鄰設備支持帶標籤路由
no neighbor 50.1.1.1 activate #關閉默認的鄰居活躍狀態
no auto-summary
no synchronization
exit-address-family
!
address-family ***v4
neighbor 50.1.1.1 activate #在此地址族下激活鄰居（CE2）
neighbor 50.1.1.1 send-community extended #發送***V4路由
exit-address-family
!
address-family ipv4 vrf *** #PE1和CE1建立EBGP鄰居關係，
redistribute connected 將學到的***路由引入到***V4
neighbor 1.1.1.1 remote-as 1000 路由裏
neighbor 1.1.1.1 activate
no auto-summary
no synchronization
exit-address-family
!
ip classless
end
r3#show run
hostname r3 #ISP自治系統邊界路由器，和另外一個AS的
! 邊界路由器相連
no ip domain lookup
!
ip cef
!
interface Loopback0
ip address 30.1.1.1 255.255.255.255 #注意子網掩碼爲4個255，防止路
! #由被聚合，LSP不能正確處理內層標籤
interface FastEthernet0/0 #和另一個AS的ASBR路由器相連的
ip address 3.1.1.1 255.255.255.0 接口，此接口不用使能MPLS
duplex half
!
interface FastEthernet1/0 #和同一AS內的PE相連的接口，此
ip address 2.1.1.2 255.255.255.0 接口需使能MPLS
duplex half
tag-switching ip
!
router ospf 1 #運行OSPF協議
log-adjacency-changes
network 2.1.1.2 0.0.0.0 area 0
network 30.1.1.1 0.0.0.0 area 0
!
router bgp 100 #運行BGP協議，AS號爲100
no bgp default route-target filter #關閉默認的路由標籤過濾功能
bgp log-neighbor-changes
neighbor 3.1.1.2 remote-as 200 #和相鄰AS的ASBR的PE建立鄰居
neighbor 20.1.1.1 remote-as 100 #和同AS內的PE建立鄰居
neighbor 20.1.1.1 update-source Loopback0
!
address-family ipv4
redistribute connected #引入直連路由
redistribute ospf 1 #引入OSPF路由
neighbor 3.1.1.2 activate #激活鄰居
neighbor 3.1.1.2 send-label #配置相鄰設備支持帶標籤路由
neighbor 3.1.1.2 route-map aa out #在出方向上應用路由圖aa
neighbor 20.1.1.1 activate #激活鄰居
neighbor 20.1.1.1 send-label #配置相鄰設備支持帶標籤路由
neighbor 20.1.1.1 next-hop-self #更改下一跳爲自己
neighbor 20.1.1.1 route-map bb out #在出方向上應用路由圖bb
no auto-summary
no synchronization
exit-address-family
!
ip classless
!
route-map aa permit 10 #創建路由圖aa,對於從本AS的PE接受的路由
set mpls-label 在向對端AS的ASBR的PE發佈時，分配MPLS標籤
!
route-map bb permit 10 #創建路由圖bb,對於向本AS內發佈的路由，如果
match mpls-label 是帶標籤的IPV4路由，爲其分配新的MPLS標籤
set mpls-label
!
end
r4#show run
hostname r4 #ISP自治系統邊界路由器，和另外一個AS的
! 邊界路由器相連
no ip domain lookup
!
ip cef
!
interface Loopback0
ip address 40.1.1.1 255.255.255.255 #注意子網掩碼爲4個255，防止路
! #由被聚合，LSP不能正確處理內層標籤
interface FastEthernet0/0 #和另一個AS的ASBR路由器相連的
ip address 3.1.1.2 255.255.255.0 接口，此接口不用使能MPLS
duplex half
!
interface FastEthernet1/0 #和同一AS內的PE相連的接口，此
ip address 4.1.1.1 255.255.255.0 接口需使能MPLS
duplex half
tag-switching ip
!
router ospf 1 #運行OSPF
log-adjacency-changes
network 4.1.1.1 0.0.0.0 area 0
network 40.1.1.1 0.0.0.0 area 0
!
router bgp 200 #運行BGP協議，AS號爲200
no bgp default route-target filter#關閉默認的路由標籤過濾功能
bgp log-neighbor-changes
neighbor 3.1.1.1 remote-as 100 #和相鄰AS的ASBR的PE建立鄰居
neighbor 50.1.1.1 remote-as 200 #和同AS內的PE建立鄰居
neighbor 50.1.1.1 update-source Loopback0
!
address-family ipv4
redistribute connected #引入直連路由
redistribute ospf 1 #引入OSPF路由
neighbor 3.1.1.1 activate #激活鄰居
neighbor 3.1.1.1 send-label #配置相鄰設備支持帶標籤路由
neighbor 3.1.1.1 route-map aa out #在出方向上應用路由圖aa
neighbor 50.1.1.1 activate #激活鄰居
neighbor 50.1.1.1 send-label #配置相鄰設備支持帶標籤路由
neighbor 50.1.1.1 next-hop-self #更改下一跳爲自己
neighbor 50.1.1.1 route-map cc out#在出方向上應用路由圖cc
no auto-summary
no synchronization
exit-address-family
!
ip classless
!
route-map aa permit 10 #創建路由圖aa,對於從本AS的PE接受的路由
set mpls-label 在向對端AS的ASBR的PE發佈時，分配MPLS標籤
!
route-map cc permit 10 #創建路由圖bb,對於向本AS內發佈的路由，如果
match mpls-label 是帶標籤的IPV4路由，爲其分配新的MPLS標籤
set mpls-label
!
End
r5#show run
hostname r5 #PE設備，是ISP和用戶相連的設備
!
no ip domain lookup
!
ip vrf *** #創建一個VRF（***路由轉發）
rd 200:1
route-target export 100:1
route-target import 100:1
!
ip cef
!
interface Loopback0
ip address 50.1.1.1 255.255.255.255
!
interface FastEthernet0/0 #在此接口綁定VRF（***實例）
ip vrf forwarding ***
ip address 5.1.1.1 255.255.255.0
duplex half
!
interface FastEthernet1/0
ip address 4.1.1.2 255.255.255.0
duplex half
tag-switching ip
!
router ospf 1
log-adjacency-changes
network 4.1.1.2 0.0.0.0 area 0
network 50.1.1.1 0.0.0.0 area 0
!
router bgp 200 #和R2上的基本原理一致
bgp log-neighbor-changes
neighbor 20.1.1.1 remote-as 100
neighbor 20.1.1.1 ebgp-multihop 10
neighbor 20.1.1.1 update-source Loopback0
neighbor 40.1.1.1 remote-as 200
neighbor 40.1.1.1 update-source Loopback0
!
address-family ipv4
redistribute connected
no neighbor 20.1.1.1 activate
neighbor 40.1.1.1 activate
neighbor 40.1.1.1 send-label
no auto-summary
no synchronization
exit-address-family
!
address-family ***v4
neighbor 20.1.1.1 activate
neighbor 20.1.1.1 send-community extended
exit-address-family
!
address-family ipv4 vrf ***
redistribute connected
neighbor 5.1.1.2 remote-as 2000
neighbor 5.1.1.2 activate
no auto-summary
no synchronization
exit-address-family
!
ip classless
End
r6#show run
hostname r6 #用戶CE設備，和ISP的PE設備相連
!
no ip domain lookup
!
ip cef
!
interface Loopback0 #和R1上的基本原理一致
ip address 60.1.1.1 255.255.255.0
!
interface FastEthernet0/0
ip address 5.1.1.2 255.255.255.0
duplex half
!
interface FastEthernet1/0
no ip address
shutdown
duplex half
!
router bgp 2000 #和R1上的基本原理一致
no synchronization
bgp log-neighbor-changes
redistribute connected
neighbor 5.1.1.1 remote-as 200
no auto-summary
!
ip classless
End
r1#traceroute
Protocol [ip]:
Target IP address: 60.1.1.1
Source address:
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Type escape sequence to abort.
Tracing the route to 60.1.1.1
1 1.1.1.2 104 msec 124 msec 44 msec
2 2.1.1.2 [MPLS: Labels 24/18 Exp 0] 252 msec 148 msec 200 msec
3 3.1.1.2 [MPLS: Labels 16/18 Exp 0] 188 msec 172 msec 120 msec
4 5.1.1.1 [AS 200] [MPLS: Label 18 Exp 0] 72 msec 208 msec 196 msec
5 5.1.1.2 [AS 200] 292 msec * 196 msec
r1#show ip route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, FastEthernet0/0
5.0.0.0/24 is subnetted, 1 subnets
B 5.1.1.0 [20/0] via 1.1.1.2, 00:47:16
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Loopback0
60.0.0.0/24 is subnetted, 1 subnets
B 60.1.1.0 [20/0] via 1.1.1.2, 00:47:16
r2#show ip route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 1 subnets
B 50.1.1.1 [200/2] via 30.1.1.1, 01:05:17
2.0.0.0/24 is subnetted, 1 subnets
C 2.1.1.0 is directly connected, FastEthernet1/0
4.0.0.0/24 is subnetted, 1 subnets
B 4.1.1.0 [200/0] via 30.1.1.1, 01:05:17
20.0.0.0/32 is subnetted, 1 subnets
C 20.1.1.1 is directly connected, Loopback0
40.0.0.0/32 is subnetted, 1 subnets
B 40.1.1.1 [200/0] via 30.1.1.1, 01:05:17
30.0.0.0/32 is subnetted, 1 subnets
O 30.1.1.1 [110/2] via 2.1.1.2, 01:10:32, FastEthernet1/0
r2#show ip route vrf ***
Routing Table: ***
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, FastEthernet0/0
5.0.0.0/24 is subnetted, 1 subnets
B 5.1.1.0 [20/0] via 50.1.1.1, 00:48:24
10.0.0.0/24 is subnetted, 1 subnets
B 10.1.1.0 [20/0] via 1.1.1.1, 01:44:40
60.0.0.0/24 is subnetted, 1 subnets
B 60.1.1.0 [20/0] via 50.1.1.1, 00:48:24
r2#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 30.1.1.1/32 0 Fa1/0 2.1.1.2
17 Aggregate 1.1.1.0/24[V] 2212
18 Untagged 10.1.1.0/24[V] 570 Fa0/0 1.1.1.1
r3#show ip route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 1 subnets
B 50.1.1.1 [20/2] via 3.1.1.2, 01:06:14
2.0.0.0/24 is subnetted, 1 subnets
C 2.1.1.0 is directly connected, FastEthernet1/0
3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 3.1.1.2/32 is directly connected, FastEthernet0/0
C 3.1.1.0/24 is directly connected, FastEthernet0/0
4.0.0.0/24 is subnetted, 1 subnets
B 4.1.1.0 [20/0] via 3.1.1.2, 01:06:14
20.0.0.0/32 is subnetted, 1 subnets
O 20.1.1.1 [110/2] via 2.1.1.1, 01:11:24, FastEthernet1/0
40.0.0.0/32 is subnetted, 1 subnets
B 40.1.1.1 [20/0] via 3.1.1.2, 01:06:14
30.0.0.0/32 is subnetted, 1 subnets
C 30.1.1.1 is directly connected, Loopback0
r3#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 20.1.1.1/32 9163 Fa1/0 2.1.1.1
17 Pop tag 3.1.1.2/32 0 Fa0/0 3.1.1.2
22 Pop tag 4.1.1.0/24 1140 Fa0/0 3.1.1.2
23 Pop tag 40.1.1.1/32 0 Fa0/0 3.1.1.2
24 16 50.1.1.1/32 9106 Fa0/0 3.1.1.2
r4#show ip route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 1 subnets
O 50.1.1.1 [110/2] via 4.1.1.2, 01:07:17, FastEthernet1/0
2.0.0.0/24 is subnetted, 1 subnets
B 2.1.1.0 [20/0] via 3.1.1.1, 01:07:06
3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 3.1.1.1/32 is directly connected, FastEthernet0/0
C 3.1.1.0/24 is directly connected, FastEthernet0/0
4.0.0.0/24 is subnetted, 1 subnets
C 4.1.1.0 is directly connected, FastEthernet1/0
20.0.0.0/32 is subnetted, 1 subnets
B 20.1.1.1 [20/2] via 3.1.1.1, 01:07:06
40.0.0.0/32 is subnetted, 1 subnets
C 40.1.1.1 is directly connected, Loopback0
30.0.0.0/32 is subnetted, 1 subnets
B 30.1.1.1 [20/0] via 3.1.1.1, 01:07:07
r4#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 50.1.1.1/32 9071 Fa1/0 4.1.1.2
17 Pop tag 3.1.1.1/32 0 Fa0/0 3.1.1.1
18 Pop tag 2.1.1.0/24 570 Fa0/0 3.1.1.1
19 16 20.1.1.1/32 9762 Fa0/0 3.1.1.1
20 Pop tag 30.1.1.1/32 0 Fa0/0 3.1.1.1
r5#show ip route
Gateway of last resort is not set
50.0.0.0/32 is subnetted, 1 subnets
C 50.1.1.1 is directly connected, Loopback0
2.0.0.0/24 is subnetted, 1 subnets
B 2.1.1.0 [200/0] via 40.1.1.1, 00:59:02
4.0.0.0/24 is subnetted, 1 subnets
C 4.1.1.0 is directly connected, FastEthernet1/0
20.0.0.0/32 is subnetted, 1 subnets
B 20.1.1.1 [200/2] via 40.1.1.1, 00:59:02
40.0.0.0/32 is subnetted, 1 subnets
O 40.1.1.1 [110/2] via 4.1.1.1, 01:07:56, FastEthernet1/0
30.0.0.0/32 is subnetted, 1 subnets
B 30.1.1.1 [200/0] via 40.1.1.1, 00:59:02
r5#show ip route vrf ***
Routing Table: ***
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
B 1.1.1.0 [20/0] via 20.1.1.1, 00:50:47
5.0.0.0/24 is subnetted, 1 subnets
C 5.1.1.0 is directly connected, FastEthernet0/0
10.0.0.0/24 is subnetted, 1 subnets
B 10.1.1.0 [20/0] via 20.1.1.1, 00:50:47
60.0.0.0/24 is subnetted, 1 subnets
B 60.1.1.0 [20/0] via 5.1.1.2, 01:43:55
r5#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 Pop tag 40.1.1.1/32 0 Fa1/0 4.1.1.1
17 Aggregate 5.1.1.0/24[V] 520
18 Untagged 60.1.1.0/24[V] 1812 Fa0/0 5.1.1.2
r6# show ip route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
B 1.1.1.0 [20/0] via 5.1.1.1, 00:51:05
5.0.0.0/24 is subnetted, 1 subnets
C 5.1.1.0 is directly connected, FastEthernet0/0
10.0.0.0/24 is subnetted, 1 subnets
B 10.1.1.0 [20/0] via 5.1.1.1, 00:51:05
60.0.0.0/24 is subnetted, 1 subnets
C 60.1.1.0 is directly connected, Loopback0
r6#traceroute
Protocol [ip]:
Target IP address: 10.1.1.1
Source address:
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Type escape sequence to abort.
Tracing the route to 10.1.1.1
1 5.1.1.1 52 msec 84 msec 16 msec
2 4.1.1.1 [MPLS: Labels 19/18 Exp 0] 180 msec 236 msec 168 msec
3 3.1.1.1 [MPLS: Labels 16/18 Exp 0] 196 msec 272 msec 144 msec
4 1.1.1.2 [AS 100] [MPLS: Label 18 Exp 0] 176 msec 264 msec 148 msec
5 1.1.1.1 [AS 100] 296 msec * 216 msec