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
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-id 2.2.2.2
network 2.2.2.2 0.0.0.0 area 0
network 23.0.0.0 0.0.0.255 area 0
router-id 3.3.3.3
network 3.3.3.3 0.0.0.0 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-vpn，建立vrf路由表
建立a公司的vrf表vpna,建立b公司的vrf表vpnb
ip vrf vpna
rd 100:1
route-target export 100:1
route-target import 100:1
ip vrf vpnb
rd 200:1
route-target export 200:1
route-target import 200:1
将下行口分别放入vpna,vpnb
interface fastethernet0/1
ip vrf forwarding vpna
ip address 172.16.40.1 255.255.255.0
interface fastethernet1/0
ip vrf forwarding vpnb
!
在r4,r5上做默认指向r1, r1上做静态往下指
ip route 0.0.0.0 0.0.0.0 172.16.40.1
!
r1做静态时要关联vrf表
ip route vrf vpna 192.168.40.0 255.255.255.0 172.16.40.2
ip route vrf vpnb 192.168.40.0 255.255.255.0 172.16.40.2
!
r1#p vrf vpna 192.168.40.1
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
ip address 172.16.60.1 255.255.255.0
ip address 172.16.70.1 255.255.255.0
!
r3,r6,r7运行ripv2协议
router rip
version 2
network 172.16.60.0
network 192.168.60.0
no auto-summary
network 172.16.70.0
network 192.168.70.0
r3运行ripv2时要关联vrf路由表
!
address-family ipv4 vrf vpnb
exit-address-family
address-family ipv4 vrf vpna
version 2
r3#p vrf vpna 192.168.60.1
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。
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 vpnv4
neighbor 3.3.3.3 activate
neighbor 3.3.3.3 send-community extended
bgp router-id 3.3.3.3
neighbor 1.1.1.1 remote-as 65001
neighbor 1.1.1.1 update-source loopback0
neighbor 1.1.1.1 activate
neighbor 1.1.1.1 send-community extended
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。
address-family ipv4 vrf vpna
！
address-family ipv4 vrf vpnb
redistribute static metric 20
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。
redistribute rip metric 20
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。
interface fastethernet0/0
mpls ip
查看ldp邻居是否建立
r2#show mpls ldp neighbor
peer ldp ident: 1.1.1.1:0; local ldp ident 2.2.2.2:0
tcp 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
fastethernet0/1, src ip addr: 23.0.0.3
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#show ip bgp vpnv4 vrf vpna
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 vpna)
*> 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 vpnv4 vrf vpnb
route distinguisher: 200:1 (default for vrf vpnb)
*>i192.168.70.0 3.3.3.3 1 100 0 i
r3
r3#show ip bgp vpnv4 vrf vpna
bgp table version is 9, local router id is 3.3.3.3
*>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 vpnv4 vrf vpnb
*> 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#p 192.168.60.1 source 192.168.40.1
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#p 192.168.70.1 source 192.168.40.1
sending 5, 100-byte icmp echos to 192.168.70.1, timeout is 2 seconds:
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。