实验拓扑：
实验需求：如图，R1,R2,R3为公网路由器，属于AS65001。R4，R6为A公司的总公司和子公司出口路由器，R5,R7为B公司的总公司和子公司的出口路由器。运营商为R4,R5连接R1的网段均部署为私网网段172.16.40.0/24 ,为R6,R7连接R3的网段部署为172.16.60.0/24和172.16.70.0/24 。
要求使A公司的总公司(40.1)能与子公司出口路由器的内网网段(60.1)通信，B公司的总公司(40.1)能与子公司出口路由器的内网网段(70.1)通信。
实验步骤：
首先进行基本配置。(R1,R3的下行口一会再配）
R1:
f0/0:12.0.0.1/24
l0:1.1.1.1/32
R2:
f0/0:12.0.0.2/24
f0/1:23.0.0.2/24
l0:2.2.2.2/32
R3
f0/0:23.0.0.3/24
l0:3.3.3.3/32
R4
f0/0:172.16.40.2/24
l0:192.168.40.1/24
R5
f0/0:172.16.40.2/24
l0:192.168.40.1/24
R6
f0/0:172.16.60.2/24
l0:192.168.60.1/24
R7
f0/0:172.16.70.2/24
l0:192.168.70.1/24
首先在R1,R2,R3上运行ospf协议。
R1
router ospf 1
router-id 1.1.1.1
network 1.1.1.1 0.0.0.0 area 0
network 12.0.0.0 0.0.0.255 area 0
!
R2
router ospf 1
router-id 2.2.2.2
network 2.2.2.2 0.0.0.0 area 0
network 12.0.0.0 0.0.0.255 area 0
network 23.0.0.0 0.0.0.255 area 0
!
R3
router ospf 1
router-id 3.3.3.3
network 3.3.3.3 0.0.0.0 area 0
network 23.0.0.0 0.0.0.255 area 0
!
测试下连通性
R1#p 3.3.3.3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/42/64 ms
2.运行mpls-***，建立vrf路由表
建立A公司的vrf表***a,建立B公司的vrf表***b
R1
ip vrf ***a
rd 100:1
route-target export 100:1
route-target import 100:1
!
ip vrf ***b
rd 200:1
route-target export 200:1
route-target import 200:1
!
将下行口分别放入***a,***b
interface FastEthernet0/1
ip vrf forwarding ***a
ip address 172.16.40.1 255.255.255.0
!
interface FastEthernet1/0
ip vrf forwarding ***b
ip address 172.16.40.1 255.255.255.0
!
在R4,R5上做默认指向R1, R1上做静态往下指
R4
ip route 0.0.0.0 0.0.0.0 172.16.40.1
!
R5
ip route 0.0.0.0 0.0.0.0 172.16.40.1
!
R1做静态时要关联vrf表
R1
ip route vrf ***a 192.168.40.0 255.255.255.0 172.16.40.2
ip route vrf ***b 192.168.40.0 255.255.255.0 172.16.40.2
!
测试下连通性
R1#p vrf ***a 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/20/24 ms
R3与R1做类似配置
R3
ip vrf ***a
rd 100:1
route-target export 100:1
route-target import 100:1
!
ip vrf ***b
rd 200:1
route-target export 200:1
route-target import 200:1
!
interface FastEthernet0/1
ip vrf forwarding ***a
ip address 172.16.60.1 255.255.255.0
!
interface FastEthernet1/0
ip vrf forwarding ***b
ip address 172.16.70.1 255.255.255.0
!
R3,R6,R7运行ripv2协议
R6
router rip
version 2
network 172.16.60.0
network 192.168.60.0
no auto-summary
!
R7
router rip
version 2
network 172.16.70.0
network 192.168.70.0
no auto-summary
R3运行ripv2时要关联vrf路由表
R3
router rip
!
address-family ipv4 vrf ***b
network 172.16.60.0
no auto-summary
version 2
exit-address-family
!
address-family ipv4 vrf ***a
network 172.16.70.0
no auto-summary
version 2
测试下连通性
R3#p vrf ***a 192.168.60.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.60.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/23/56 ms
现在私网网段已经搞定了。
3.在R1,R3上运行MP-BGP协议，建立IBGP邻居。
R1
router bgp 65001
bgp router-id 1.1.1.1
neighbor 3.3.3.3 remote-as 65001
neighbor 3.3.3.3 update-source Loopback0
!
激活MP-BGP邻居
address-family ***v4
neighbor 3.3.3.3 activate
neighbor 3.3.3.3 send-community extended
exit-address-family
!
R3
router bgp 65001
bgp router-id 3.3.3.3
neighbor 1.1.1.1 remote-as 65001
neighbor 1.1.1.1 update-source Loopback0
!
address-family ***v4
neighbor 1.1.1.1 activate
neighbor 1.1.1.1 send-community extended
exit-address-family
!
在R1的BGP上发布两条192.168.40.0/24路由,这里采用直接network 和重发布两种方法。
R1
router bgp 65001
address-family ipv4 vrf ***a
network 192.168.60.0
exit-address-family
！
address-family ipv4 vrf ***b
redistribute static metric 20
exit-address-family
!
在R3的BGP上，将ripv2重发布进bgp,同时也要将bgp协议重发布进ripv2，使得回程可达。
R3
router bgp 65001
address-family ipv4 vrf ***a
redistribute rip metric 20
exit-address-family
！
router bgp 65001
address-family ipv4 vrf ***b
redistribute rip metric 20
exit-address-family
！
router rip
address-family ipv4 vrf ***a
redistribute bgp 65001 metric 3
!
router rip
address-family ipv4 vrf ***b
redistribute bgp 65001 metric 3
!
4.别忘记R2并没有运行BGP,并无私网路由，此时会造成路由黑洞，因此，在R1,R2,R3上可以运行ldp协议来解决。
R1
interface FastEthernet0/0
mpls ip
!
R2
interface FastEthernet0/0
mpls ip
!
interface FastEthernet0/1
mpls ip
!
R3
interface FastEthernet0/0
mpls ip
!
查看ldp邻居是否建立
R2
R2#show mpls ldp neighbor
Peer LDP Ident: 1.1.1.1:0; Local LDP Ident 2.2.2.2:0TCP connection: 1.1.1.1.646 - 2.2.2.2.21318
State: Oper; Msgs sent/rcvd: 97/98; Downstream
Up time: 01:18:42
LDP discovery sources:
FastEthernet0/0, Src IP addr: 12.0.0.1
Addresses bound to peer LDP Ident:
12.0.0.1 1.1.1.1
Peer LDP Ident: 3.3.3.3:0; Local LDP Ident 2.2.2.2:0
TCP connection: 3.3.3.3.14076 - 2.2.2.2.646
State: Oper; Msgs sent/rcvd: 99/97; Downstream
Up time: 01:18:41
LDP discovery sources:
FastEthernet0/1, Src IP addr: 23.0.0.3
Addresses bound to peer LDP Ident:
23.0.0.3 3.3.3.3
没问题，在R1,R3上查看是否学习到对方的私网路由
R1
R1#show ip bgp ***v4 vrf ***a
BGP table version is 9, local router ID is 1.1.1.1
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 100:1 (default for vrf ***a)
*> 192.168.40.0 172.16.40.2 0 32768 i
*>i192.168.60.0 3.3.3.3 1 100 0 i
R1#show ip bgp ***v4 vrf ***b
BGP table version is 9, local router ID is 1.1.1.1
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 200:1 (default for vrf ***b)
*> 192.168.40.0 172.16.40.2 0 32768 i
*>i192.168.70.0 3.3.3.3 1 100 0 i
R3
R3#show ip bgp ***v4 vrf ***a
BGP table version is 9, local router ID is 3.3.3.3
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 100:1 (default for vrf ***a)
*>i192.168.40.0 1.1.1.1 0 100 0 i
*> 192.168.60.0 172.16.60.2 1 32768 i
R3#show ip bgp ***v4 vrf ***b
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 200:1 (default for vrf ***b)
*>i192.168.40.0 1.1.1.1 0 100 0 i
*> 192.168.70.0 172.16.70.2 1 32768 i
可以发现已经互相学习到了
最后进行连通性测试
R4
R4#p 192.168.60.1 source 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.60.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.40.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 60/78/116 ms
R4#
R5
R5#p 192.168.70.1 source 192.168.40.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.70.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.40.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 68/92/128 ms
可以通信了，实验结束。