MPLS的模拟学习过程

1、场景拓扑

使用小凡模拟器搭建了如下网络拓扑，使用的镜像为：c3640-jk9o3s-mz.122-15.T9.bin

2、术语解释

LSR:标签交换路由器，这里的LSR就是P

边缘LSR:只要一台LSR拥有非MPLS邻居，那么就可以将他看成一台边界LSR,这里的边界LSR就是PE

LSP()：标签交换路径

FEC(转发等价类):可以将转发等价类概念想象为一组以相同的方式，走相同的路径，按一致的转发优先级进行转发的数据包。

TDP():标记分发协议

LDP():标签分发协议

3、基本配置

3.1 基本IP的配置

CE1

hostname CE1

no ip domain lookup

no voice hpi capture buffer

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

interface Ethernet0/0

 ip address 192.168.1.1 255.255.255.252

 half-duplex

PE1

hostname PE1

no ip domain lookup

   interface Loopback0

 ip address 2.2.2.2 255.255.255.255

!

interface Ethernet0/0

 ip address 192.168.1.2 255.255.255.252

 half-duplex

!

interface Ethernet0/1

 ip address 10.1.1.1 255.255.255.252

 half-duplex

!

hostname P

no ip domain lookup

interface Loopback0

 ip address 3.3.3.3 255.255.255.255

!

interface Ethernet0/0

 ip address 10.1.1.5 255.255.255.252

 half-duplex

!

interface Ethernet0/1

 ip address 10.1.1.2 255.255.255.252

 half-duplex

PE2

hostname PE2

no ip domain lookup

interface Loopback0

 ip address 4.4.4.4 255.255.255.255

!

interface Ethernet0/0

 ip address 10.1.1.6 255.255.255.252

 half-duplex

!

interface Ethernet0/1

 ip address 192.168.2.1 255.255.255.252

 half-duplex

!

CE2

hostname CE2

no ip domain lookup

!

interface Loopback0

 ip address 5.5.5.5 255.255.255.255

!

interface Ethernet0/0

 no ip address

 shutdown

 half-duplex

!

interface Ethernet0/1

 ip address 192.168.2.2 255.255.255.252

 half-duplex

!

3.2 MPLS VPN实验

主要的配置在PE和PE2

分别如下步骤：

3.2.1 pe1 p pe2 路由器之间运行 ospf. 将所有的路由宣告

例如在pe1执行如下命令

router ospf 10

 router-id 2.2.2.2

network 2.2.2.2 0.0.0.0 area 0

 network 10.1.1.0 0.0.0.3 area 0

3.2.2 启用 ip cef 验证现在的路由是基于每一跳

例如在pe1上执行如下命令

ip cef

3.2.3 启用 vrf rd 用来唯一区别不同的 vpn

创建了vrf，并定义路由区别符(RD)和路由目标(RT)

ip vrf vpna

rd 100:2

route-target export 100:1

route-target import 100:1

3.2.4 启用 ibgp 主要用来承载大量的私有前缀

例如在pe1上执行如下

pe1(config)#router bgp 100

pe1(config-router)#bgp router-id 2.2.2.2

pe1(config-router)#nei 4.4.4.4 remote-as 100

pe1(config-router)#nei 4.4.4.4 update-source Loopback0

pe1(config-router)# no auto-summary

pe1(config-router)# no synchronization

pe1(config-router)#exit

激活标准的ipv4 bgp会话，这里的进程100应该是进程号，使用100这个进程号与邻居4.4.4.4进行会话

BGP进程通过使用BGP自身的地址家族，来激活携带vpn-ipv4前缀的MP-IBGP会话，在这里将邻居激活，neighbor 4.4.4.4 send-community extended(不输入也会默认添加)这个命令将指示BGP通告扩展团体属性。

3.2.5 启用 address-family vpnv4 的扩展团体属性

pe1(config)#router bgp 100

pe1(config-router)#address-family vpnv4

pe1(config-router-af)#nei 4.4.4.4 activate 注意在这里要激活邻居。

pe1(config-router-af)# neighbor 4.4.4.4 send-community extended

pe1(config-router-af)#exi

pe1(config-router)#exit

3.2.6 启用 address-family ipv4 vrf vpna

pe1(config)#router bgp 100

pe1(config-router)#address-family ipv4 vrf vpna

pe1(config-router-af)#no au

pe1(config-router-af)#no sy

pe1(config-router-af)#end

客户路由添加到vrf后，需要跨越mpls-vpn主干网通告这些路由，mp-ibgp将这些路由作为vpn-ipv4前缀，为此，需要配置BGP进程中的路由环境，用来告诉BGP需要通告的vrf路由,这里告诉BGP需要通告的vrf为vpna

3.2.7 将vpn 应用到接口中 , 注意是 pe 与 ce 相连的接口

pe1(config)#int e0/0

pe1(config-if)#ip vrf forwarding vpna

pe1(config-if)#ip add 192.168.1.2 255.255.255.252

pe1(config-if)#end

只有运行cef交换的接口才能够与vrf相关联，cef交换机制是mpls/vpn数据成功转发的首要条件，因为标签压入是通过cef交换路径完成的

注：将接口关联到一个vrf后，他的ip地址将从全局路由表中删除

3.2.8 在ce与pe上，增加 ce 到 pe 的路由。可以是静态， ospf eigrp 或是 ebgp ripv2，此实验使用静态路由

例如在ce1和pe1上执行如下命令

ce1(config)#ip route 5.5.5.5 255.255.255.255 192.168.1.2

pe1(config)#ip route vrf vpna 1.1.1.1 255.255.255.255 192.168.1.1

3.2.9 将静态路由重分布到 address-family ipv4 vrf vpna 中(bgp学习静态)

pe1(config)#router bgp 100

pe1(config-router)# address-family ipv4 vrf vpna

pe1(config-router-af)# redistribute static

pe1(config-router-af)#end

3.2.10 启用 mpls ip，注意，是在 pe 与 p 相连的接口上启用 mpls ip

interface Ethernet0/1

 ip address 10.1.1.1 255.255.255.252

 half-duplex

 tag-switching ip

3.2.11 测试 mpls 交换

全部设备配置完后，在ce1测试

CE1#ping 5.5.5.5 so 1.1.1.1 re 10

Type escape sequence to abort.

Sending 10, 100-byte ICMP Echos to 5.5.5.5, timeout is 2 seconds:

Packet sent with a source address of 1.1.1.1

!!!!!!!!!!

Success rate is 100 percent (10/10), round-trip min/avg/max = 20/38/112 ms

以下每台设备的配置：

CE1配置

设置去往5.5.5.5的静态路由

hostname CE1

no ip domain lookup

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

!

interface Ethernet0/0

 ip address 192.168.1.1 255.255.255.252

 half-duplex

!

ip route 5.5.5.5 255.255.255.255 192.168.1.2

PE1配置

hostname PE1

no ip domain lookup

ip vrf vpna

 rd 100:2

 route-target export 100:1

 route-target import 100:1

!

ip cef

ip audit notify log

ip audit po max-events 100

mpls ldp logging neighbor-changes

interface Loopback0

 ip address 2.2.2.2 255.255.255.255

!

interface Ethernet0/0

 ip vrf forwarding vpna

 ip address 192.168.1.2 255.255.255.252

 half-duplex

!

interface Ethernet0/1

 ip address 10.1.1.1 255.255.255.252

 half-duplex

 tag-switching ip

!

router ospf 10

 router-id 2.2.2.2

network 2.2.2.2 0.0.0.0 area 0

 network 10.1.1.0 0.0.0.3 area 0

!

router bgp 100

 no synchronization

 bgp router-id 2.2.2.2

 bgp log-neighbor-changes

 neighbor 4.4.4.4 remote-as 100

 neighbor 4.4.4.4 update-source Loopback0

 no auto-summary

 !

 address-family vpnv4

 neighbor 4.4.4.4 activate

 neighbor 4.4.4.4 send-community extended

 no auto-summary

 exit-address-family

 !

 address-family ipv4 vrf vpna

 redistribute static

 no auto-summary

 no synchronization

 exit-address-family

!

ip route vrf vpna 1.1.1.1 255.255.255.255 192.168.1.1

P配置

hostname P

no ip domain lookup

ip cef

interface Loopback0

 ip address 3.3.3.3 255.255.255.255

!

interface Ethernet0/0

 ip address 10.1.1.5 255.255.255.252

 half-duplex

 tag-switching ip

!

interface Ethernet0/1

 ip address 10.1.1.2 255.255.255.252

 half-duplex

 tag-switching ip

router ospf 10

 router-id 3.3.3.3

 log-adjacency-changes

 network 3.3.3.3 0.0.0.0 area 0

 network 10.1.1.0 0.0.0.3 area 0

 network 10.1.1.4 0.0.0.3 area 0

PE2配置

hostname PE2

no ip domain lookup

ip vrf vpnb

 rd 100:3

 route-target export 100:1

 route-target import 100:1

!

ip cef

mpls ldp logging neighbor-changes

interface Loopback0

 ip address 4.4.4.4 255.255.255.255

!

interface Ethernet0/0

 ip address 10.1.1.6 255.255.255.252

 half-duplex

 tag-switching ip

!

interface Ethernet0/1

 ip vrf forwarding vpnb

 ip address 192.168.2.1 255.255.255.252

 half-duplex

router ospf 10

 router-id 4.4.4.4

 log-adjacency-changes

 network 4.4.4.4 0.0.0.0 area 0

 network 10.1.1.4 0.0.0.3 area 0

!

router bgp 100

 no synchronization

 bgp router-id 4.4.4.4

 bgp log-neighbor-changes

 neighbor 2.2.2.2 remote-as 100

 neighbor 2.2.2.2 update-source Loopback0

 no auto-summary

 !

 address-family vpnv4

 neighbor 2.2.2.2 activate

 neighbor 2.2.2.2 send-community extended

 no auto-summary

 exit-address-family

 !

 address-family ipv4 vrf vpnb

 redistribute static

 no auto-summary

 no synchronization

 exit-address-family

!

ip route vrf vpnb 5.5.5.5 255.255.255.255 192.168.2.2

CE2

hostname CE2

no ip domain lookup

interface Loopback0

 ip address 5.5.5.5 255.255.255.255

!

interface Ethernet0/0

 no ip address

 shutdown

 half-duplex

!

interface Ethernet0/1

 ip address 192.168.2.2 255.255.255.252

 half-duplex

ip route 1.1.1.1 255.255.255.255 192.168.2.1