How to limit different bandwidth usage without rate-limit command in a interface?

在CCIE考題中最難不是指令的記憶及設定，而是題意內容的了解，尤其對於非英文系國家的人來說更容易被題目的字裏行間所誤導。其中最容易confused的就是QoS相關的題目，因為它通常會伴隨著數字及不同的單位傳輸速率，所以我找了幾個例子來讓各位了解這類題目及相對應的解法：

Question:

• Received traffic from 172.16.0.0/16 under 512Kbps should be marked as flash-override
• Received traffic from 172.16.0.0/16 over 512Kbps should be marked as priority
• Received traffic from 172.16.0.0/16 over 1.5Mbps should be dropped
• DO NOT use rate-limit command to accomplish this.

Router(config)#ip access-list extended QOS_SOURCE
Router(config-ext-nacl)#permit ip 172.16.0.0 0.0.255.255 any
!
Router(config)#class-map QOS_SOURCE
Router(config-cmap)#match access-group name QOS_SOURCE
!
Router(config)#policy-map QOS_MARK
Router(config-pmap)#class QOS_SOURCE
Router(config-pmap-c)#police cir 512000
Router(config-pmap-c-ploice)#conform-action set-prec-transmit 4
Router(config-pmap-c-ploice)#exceed-action set-prec-transmit 1
Router(config-pmap-c-ploice)#violate-action set-prec-transmit 1
!
Router(config)#policy-map QOS_POLICE
Router(config-pmap)#class class-default
Router(config-pmap-c)#police 1500000
Router(config-pmap-c)#service-policy QOS_MARK
!
Router(config)#int f0/0
Router(config-if)#service-policy input QOS_POLICE