四、根据数据包的大小来做策略路由走向：
 

1、我先把R4上的pbr1下再做一个match:
R4(config)#route-map pbr1 permit 1

R4(config-route-map)#match length 0 600 ( 匹配一个最小为 0  ，最大为 600 的数据包 )

 

R4(config)#route-map pbr2 permit 2

R4(config-route-map)#match length 0 800  ( 匹配一个最小为 601 ，最大为 800 的数据包 )

2、在R4上show route-map 看一下：
R4(config)#do sho route-map

route-map pbr1, permit, sequence 1

  Match clauses:

  Set clauses:

    ip next-hop 192.168.34.3

  Policy routing matches: 0 packets, 0 bytes

route-map pbr2, permit, sequence 2

  Match clauses:

    ip address (access-lists): 2

    length 601 800

  Set clauses:

    ip next-hop 192.168.34.3

  Policy routing matches: 0 packets, 0 bytes

 
3、我现在在R5上用扩展ping
R5#ping ip   

Target IP address: 1.1.1.1

Repeat count [5]: 5

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 5.5.5.5

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

Packet sent with a source address of 5.5.5.5

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 216/325/404

4、再到R4上看一下route-map
route-map pbr1, permit, sequence 1

  Match clauses:

    length 0 600

  Set clauses:

    ip next-hop 192.168.24.2

  Policy routing matches: 5 packets, 520 bytes    （走这条链路了是 520bytes ）

route-map pbr2, permit, sequence 2

  Match clauses:

    ip address (access-lists): 2

    length 601 800

  Set clauses:

    ip next-hop 192.168.34.3

  Policy routing matches: 0 packets, 0 bytes

5、同样在R6上用扩展ping 700看一下会走哪里？
R6#ping ip        

Target IP address: 1.1.1.1

Repeat count [5]: 5

Datagram size [100]: 700

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 6.6.6.6

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]:

Sweep range of sizes [n]:

Type escape sequence to abort.

Sending 5, 700-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

Packet sent with a source address of 6.6.6.6

!!!!!

Success rat

 
6、再次show route-map
R4#  show route-map

route-map pbr1, permit, sequence 1

  Match clauses:

    length 0 600

  Set clauses:

    ip next-hop 192.168.24.2

  Policy routing matches: 5 packets, 520 bytes    （这里还是 520bytes ）

route-map pbr2, permit, sequence 2

  Match clauses:

    ip address (access-lists): 2

    length 601 800

  Set clauses:

    ip next-hop 192.168.34.3

  Policy routing matches: 5 packets, 3520 bytes  （这里却到了 3520bytes ）

 
7、我在R6上traceroute ，因为traceroute 过去的话也会小于700
R6#traceroute ip    

 

Target IP address: 1.1.1.1

Source address: 6.6.6.6

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 1.1.1.1

 

  1 192.168.46.4 84 msec 128 msec 92 msec

  2 192.168.24.2 188 msec 220 msec 280 msec

  3 192.168.12.1 216 msec *  260 msec             （小于 700 ，所以就走左边链路了）