配置步骤

定义acl，匹配SwitchA访问SwitchB的流量，在做流量统计时应尽量保证匹配的情况精确，避免抓取到其他业务流量，使流量统计不准确。

[H3C]acl number 999

[H3C-acl-adv-999]description traffic accounting for host SwitchA to host SwitchB

[H3C-acl-adv-999]rule 10 permit icmp source 2.2.2.2 0 destination 3.3.3.3 0 

定义流分类，匹配acl定义的PCA访问PCB的web流量。

[H3C]traffic classifier traffic_accounting_from_SwitchA_to_SwitchB

[H3C-classifier-traffic_accounting_from_SwitchA_to_SwitchB]if-match acl 999

定义流行为，统计报文个数

[H3C]traffic behavior traffic_accounting_from_SwitchA_to_SwitchB

[H3C-behavior-traffic_accounting_from_SwitchA_to_SwitchB]accounting packet

定义qos策略，关联流分类和流行为

[H3C]qos policy traffic_accounting_from_SwitchA_to_SwitchB

[H3C-qospolicy-traffic_accounting_from_SwitchA_to_SwitchB]classifier traffic_accounting_from_SwitchA_to_SwitchB behavior traffic_accounting_from_SwitchA_to_SwitchB

在2/0/1的入方向和2/0/2的出访问下发qos策略，来统计报文是否到达设备和是否被设备转发给SwitchB。

[H3C]interface GigabitEthernet2/0/1

[H3C-GigabitEthernet2/0/1]qos apply policy traffic_accounting_from_SwitchA_to_SwitchB inbound

[H3C]interface GigabitEthernet2/0/2

[H3C-GigabitEthernet2/0/2]qos apply policy traffic_accounting_from_SwitchA_to_SwitchB outbound

使SwitchA访问SwitchB，查看接口GigabitEthernet2/0/1流量统计结果

[H3C]display qos policy interface GigabitEthernet 2/0/1

  Interface: GigabitEthernet2/0/1

  Direction: Inbound

  Policy: traffic_accounting_from_SwitchA_to_SwitchB
   Classifier: traffic_accounting_from_SwitchA_to_SwitchB
     Operator: AND
     Rule(s) : If-match acl 999
     Behavior: traffic_accounting_from_SwitchA_to_SwitchB
      Accounting Enable:
        5 (Packets)

根据结果看出有5个报文进行交换机。查看接口GigabitEthernet2/0/2流量统计结果

[H3C]display qos policy interface GigabitEthernet 2/0/2

  Interface: GigabitEthernet2/0/2

  Direction: Outbound

  Policy: traffic_accounting_from_SwitchA_to_SwitchB
   Classifier: traffic_accounting_from_SwitchA_to_SwitchB
     Operator: AND
     Rule(s) : If-match acl 999
     Behavior: traffic_accounting_from_SwitchA_to_SwitchB
      Accounting Enable:
        5 (Packets)

有5个报文从交换机发出，说明从A到B转发正常

配置文件

#
acl number 999 
 description traffic accounting for host SwitchA to host SwitchB
 rule 10 permit icmp source 2.2.2.2 0 destination 3.3.3.3 0 acl number 
#
traffic classifier traffic_accounting_from_SwitchA_to_SwitchB 
 if-match acl 999
#
traffic behavior traffic_accounting_from_SwitchA_to_SwitchB
 accounting packet
#
qos policy traffic_accounting_from_SwitchA_to_SwitchB
 classifier traffic_accounting_from_SwitchA_to_SwitchB behavior traffic_accounting_from_SwitchA_to_SwitchB
#
interface GigabitEthernet2/0/1
 qos apply policy traffic_accounting_from_SwitchA_to_SwitchB inbound
#
interface GigabitEthernet2/0/2
 qos apply policy traffic_accounting_from_SwitchA_to_SwitchB outbound

注意事项

1. 对匹配的流量计一定要尽量精确，避免其他流量影响统计结果。

2. 注意流量双向性和qos策略下发的方向要正确下发。