User's Manual

18-12
Example 3:
Figure 18-7 Typical QoS topology
As shown in the figure, inside the block is a QoS domain, Switch1 classifies different traffics and assigns
different IP precedences. For example, set CoS precedence for packets from segment 192.168.1.0 to 5 on
port ethernet1/0/1(set the internal priority to 40, set the default intp-dscp mapping to 40-40, the corresponding
IP precedence to 5). The port connecting to switch2 is a trunk port. In Switch2, set port ethernet 1/0/1 that
connecting to swtich1 to trust dscp. Thus inside the QoS domain, packets of different priorities will go to
different queues and get different bandwidth.
The configuration steps are listed below:
QoS configuration in Switch1:
Switch#config
Switch(config)#access-list 1 permit 192.168.1.0 0.0.0.255
Switch(config)#class-map c1
Switch(Config-ClassMap-c1)#match access-group 1
Switch(Config-ClassMap-c1)#exit
Switch(config)#policy-map p1
Switch(Config-PolicyMap-p1)#class c1
Switch(Config-PolicyMap-p1-Class-c1)#set ip precedence 40
Switch(Config-PolicyMap-p1-Class-c1)#exit
Switch(Config-PolicyMap-p1)#exit
Switch(config)#interface ethernet 1/0/1
Switch(Config-If-Ethernet1/0/1)#service-policy input p1
Server
Switch3
Switch1
Switch2
Trunk
QoS area