0.原理
0.1、策略路由原理
策略路由：通过定义策略和应用，实现数据流量按照规划的路径走，比如张三走联通出口，李四走电信出口（策略路由的优先级比普通路由表优先级更高）。
路由策略是通过ACL等方式控制路由发布，让对方学到适当路由条目，比如有20条路由条目，只想让某个路由器学到10条，可以通过路由策略进行过滤。
路由策略和策略路由是两种不同的机制，主要区别如下：
| 路由策略 | 策略路由 |
|---|---|
| 基于策略控制路由信息的引入、发布、接收 | 基于策略控制报文的转发，即可以不按照路由表转发报文，而是通过按照策略需要转发，转发失败后再通过查找路由表转发 |
| 基于控制平面，为路由协议和路由表服务 | 基于转发平面，为转发策略服务 |
| 与路由协议结合完成策略，应用命令route-policy | 需要手工逐跳配置，以保证报文按策略转发，应用命令traffic-policy |
1.拓扑图
2.实验步骤
实现的效果：
三个路由器，分配配置RIPv2，OSPF，分别学到路由信息，并设备cost。
在R1中配置IP地址和RIPv2
<Huawei>sys
[Huawei]sysname R1
[R1]interface g0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.1.1.1 30
[R1-GigabitEthernet0/0/0]int lo0
[R1-LoopBack0]ip add 10.1.1.1 24
[R1-LoopBack0]int lo1
[R1-LoopBack1]ip add 10.1.2.1 24
[R1-LoopBack1]int lo2
[R1-LoopBack2]ip add 10.1.3.1 24
[R1-LoopBack2]q
[R1]rip
[R1-rip-1]version 2
[R1-rip-1]network 12.0.0.0
[R1-rip-1]network 10.0.0.0
[R1-rip-1]q
在R2中配置IP地址、RIPv2、OSPF
<Huawei>sys
[Huawei]sysname R2
[R2]int g0/0/0
[R2-GigabitEthernet0/0/0]ip add 12.1.1.2 30
[R2-GigabitEthernet0/0/0]int g0/0/1
[R2-GigabitEthernet0/0/1]ip add 23.1.1.1 30
[R2-GigabitEthernet0/0/1]q
[R2]ping 12.1.1.1
PING 12.1.1.1: 56 data bytes, press CTRL_C to break
Reply from 12.1.1.1: bytes=56 Sequence=1 ttl=255 time=70 ms
Reply from 12.1.1.1: bytes=56 Sequence=2 ttl=255 time=30 ms
Reply from 12.1.1.1: bytes=56 Sequence=3 ttl=255 time=10 ms
Reply from 12.1.1.1: bytes=56 Sequence=4 ttl=255 time=10 ms
Reply from 12.1.1.1: bytes=56 Sequence=5 ttl=255 time=20 ms
--- 12.1.1.1 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 10/28/70 ms
[R2]rip
[R2-rip-1]version 2
[R2-rip-1]network 12.0.0.0
[R2-rip-1]q
[R2]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 13 Routes : 13
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
10.1.2.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
10.1.3.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
12.1.1.0/30 Direct 0 0 D 12.1.1.2 GigabitEthernet0/0/0
12.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
12.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
23.1.1.0/30 Direct 0 0 D 23.1.1.1 GigabitEthernet0/0/1
23.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/1
23.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[R2]ospf
[R2-ospf-1]are
[R2-ospf-1]area 0
[R2-ospf-1-area-0.0.0.0]net
[R2-ospf-1-area-0.0.0.0]network 23.1.1.0 0.0.0.3
[R2-ospf-1-area-0.0.0.0]q
[R2-ospf-1]
在R3中配置，IP地址、OSPF
<Huawei>sys
[Huawei]sysname R3
[R3]int g0/0/0
[R3-GigabitEthernet0/0/0]ip add 23.1.1.2 30
[R3-GigabitEthernet0/0/0]int lo0
[R3-LoopBack0]ip add 30.1.1.1 24
[R3-LoopBack0]int lo1
[R3-LoopBack1]ip add 30.1.2.1 24
[R3-LoopBack1]int lo2
[R3-LoopBack2]ip add 30.1.3.1 24
[R3-LoopBack2]q
[R3]ospf 1
[R3-ospf-1]area 0
[R3-ospf-1-area-0.0.0.0]network 23.1.1.0 0.0.0.3
[R3-ospf-1-area-0.0.0.0]network 0.0.0.0 0.0.0.0
[R3-ospf-1-area-0.0.0.0]q
[R3-ospf-1]q
在R2中查看路由表有没有学到R2中的路由信息
<R2>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 16 Routes : 16
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
10.1.2.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
10.1.3.0/24 RIP 100 1 D 12.1.1.1 GigabitEthernet0/0/0
12.1.1.0/30 Direct 0 0 D 12.1.1.2 GigabitEthernet0/0/0
12.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
12.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
23.1.1.0/30 Direct 0 0 D 23.1.1.1 GigabitEthernet0/0/1
23.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/1
23.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/1
30.1.1.1/32 OSPF 10 1 D 23.1.1.2 GigabitEthernet0/0/1
30.1.2.1/32 OSPF 10 1 D 23.1.1.2 GigabitEthernet0/0/1
30.1.3.1/32 OSPF 10 1 D 23.1.1.2 GigabitEthernet0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0经过上述配置之后，R2拥有R1和R3的路由信息，但是R1和R3并没有彼此的路由信息，需要在R2上进行路由的重分发。
在R2中配置，实现指定的网段，被引用到R3中
1.配置ACL，允许10.1.2.0 和 10.1.3.0 两个网段
[R2]acl 2000
[R2-acl-basic-2000]rule 10 permit source 10.1.2.0 0.0.0.255
[R2-acl-basic-2000]rule 20 permit source 10.1.3.0 0.0.0.255
[R2-acl-basic-2000]q
2.配置路由策略
[R2]route-policy fromR1 permit ?
node Node of the route policy
[R2]route-policy fromR1 permit node ?
INTEGER<0-65535> Index of the node
[R2]route-policy fromR1 permit node 10
Info: New Sequence of this List.
[R2-route-policy]if-match acl 2000
[R2-route-policy]q
3.通过R3中的OSPF来引入网段，
import-route rip 1 增加后面的路由策略进行限制，指定特定的网段被引入：route-policy fromR1
[R2]ospf 1
[R2-ospf-1]import-route rip 1 ?
cost Set cost
route-policy Route policy
tag Specify route tag
type Metric type of the imported external routes
<cr> Please press ENTER to execute command
[R2-ospf-1]import-route rip 1 route-policy ?
STRING<1-40> Name of the route policy
fromR1 Name of the route policy
[R2-ospf-1]import-route rip 1 route-policy fromR1
[R2-ospf-1]q在R3中查看路由表，指定的路由信息已经被引入：
如：10.1.2.0/24 O_ASE 150 1
<R3>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 18 Routes : 18
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.2.0/24 O_ASE 150 1 D 23.1.1.1 GigabitEthernet0/0/0
10.1.3.0/24 O_ASE 150 1 D 23.1.1.1 GigabitEthernet0/0/0
23.1.1.0/30 Direct 0 0 D 23.1.1.2 GigabitEthernet0/0/0
23.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
23.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
30.1.1.0/24 Direct 0 0 D 30.1.1.1 LoopBack0
30.1.1.1/32 Direct 0 0 D 127.0.0.1 LoopBack0
30.1.1.255/32 Direct 0 0 D 127.0.0.1 LoopBack0
30.1.2.0/24 Direct 0 0 D 30.1.2.1 LoopBack1
30.1.2.1/32 Direct 0 0 D 127.0.0.1 LoopBack1
30.1.2.255/32 Direct 0 0 D 127.0.0.1 LoopBack1
30.1.3.0/24 Direct 0 0 D 30.1.3.1 LoopBack2
30.1.3.1/32 Direct 0 0 D 127.0.0.1 LoopBack2
30.1.3.255/32 Direct 0 0 D 127.0.0.1 LoopBack2
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
在R2中配置，实现指定的网段，被引用到R1中
[R2]acl 2001
[R2-acl-basic-2001]rule 20 permit source 30.1.2.0 0.0.0.255
[R2-acl-basic-2001]rule 30 permit source 30.1.3.0 0.0.0.255
[R2-acl-basic-2001]q
[R2]route-policy ?
STRING<1-40> Name of the route policy
fromR1 Name of the route policy
fromR3 Name of the route policy
[R2]route-policy fromR3 permit ?
node Node of the route policy
[R2]route-policy fromR3 permit node 20
[R2-route-policy]if-match acl 2001
[R2-route-policy]apply cost 10
[R2-route-policy]q
[R2]rip 1
[R2-rip-1]import-route ospf 1 route-policy ?
STRING<1-40> Name of the route policy
fromR1 Name of the route policy
fromR3 Name of the route policy
[R2-rip-1]import-route ospf 1 route-policy fromR3
[R2-rip-1]q
在R1中查看路由表，指定的路由信息已经被引入：
<R1>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 18 Routes : 18
Destination/Mask Proto Pre Cost Flags NextHop Interface
10.1.1.0/24 Direct 0 0 D 10.1.1.1 LoopBack0
10.1.1.1/32 Direct 0 0 D 127.0.0.1 LoopBack0
10.1.1.255/32 Direct 0 0 D 127.0.0.1 LoopBack0
10.1.2.0/24 Direct 0 0 D 10.1.2.1 LoopBack1
10.1.2.1/32 Direct 0 0 D 127.0.0.1 LoopBack1
10.1.2.255/32 Direct 0 0 D 127.0.0.1 LoopBack1
10.1.3.0/24 Direct 0 0 D 10.1.3.1 LoopBack2
10.1.3.1/32 Direct 0 0 D 127.0.0.1 LoopBack2
10.1.3.255/32 Direct 0 0 D 127.0.0.1 LoopBack2
12.1.1.0/30 Direct 0 0 D 12.1.1.1 GigabitEthernet0/0/0
12.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
12.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/0/0
30.1.2.1/32 RIP 100 1 D 12.1.1.2 GigabitEthernet0/0/0
30.1.3.1/32 RIP 100 1 D 12.1.1.2 GigabitEthernet0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0