Cisco QoS (priority queuing优先队列)

PQ ensures that important traffic gets the fastest handling at each point where it is used. It was designed to give strict priority to important traffic.

pq确保重要数据得到最快的处理在每一个点。这是旨在给予严格的优先级以保证重要的数据转发。

实验要求：

1 将udp协议的16333端口至35252端口都设为低优先级

2 将rip设为高优先级

实验配置

R1(config)#priority-list 1 protocol ip low list 100           //建立优先级列表1，将与access-list 100匹配的流量设为低优先级

R1(config)#access-list 100 permit udp any range 16333 35252 any range 16333 35252   //range命令是设定一个端口范围


R1(config)#priority-list 1 protocol ip high udp rip
R1(config)#int f0/0

R1(config-if)#priority-group 1                     //将优先级列表1应用到接口f0/0上

My3377#show queueing

List   Queue Args

1      low    protocol ip          list 100

1      high   protocol ip          udp port rip

My3377#show ip int s2/1

Serial2/1 is up, line protocol is down

Internet protocol processing disabled

My3377#show int s2/1

Serial2/1 is up, line protocol is down

Hardware is M4T

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

    reliability 255/255, txload 1/255, rxload 1/255

Encapsulation HDLC, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input never, output 00:00:08, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: priority-list 1

Output queue (queue priority: size/max/drops):

    high: 0/20/0, medium: 0/40/0, normal: 0/60/0, low: 0/80/0

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

    0 packets input, 0 bytes, 0 no buffer

    Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

    0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

    13 packets output, 930 bytes, 0 underruns

    0 output errors, 0 collisions, 3 interface resets

    0 ou