SGS-6340 Series User Manual

23-138
As shown in the figure, inside the block is a QoS domain, Switch 1 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 ethernet1/1. The port connecting to switch 2 is a trunk port.
In Switch 2, set port ethernet 1/1 that connecting to swtich1 to trust cos. Thus inside the QoS
domain, packets of different priorities will go to different queues and get a 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 5
Switch(Config-PolicyMap-p1-Class-c1)#exit
Switch(Config-PolicyMap-p1)#exit
Switch(config)#interface ethernet 1/1
Switch(Config-If-Ethernet1/1)#service-policy input p1
QoS configuration in Switch2:
Switch#config
Switch(config)#interface ethernet 1/1
Switch(Config-If-Ethernet1/1)#mls qos trust cos
23.4 QoS Troubleshooting
 trust cos can be used with other trust or Policy Map.
 trust dscp can be used with other trust or Policy Map. This configuration takes effect
to IPv4 and IPv6 packets.
 trust dscp and trust cos may be configured at the same time, the priority is:
DSCP>COS.
 If the dynamic VLAN (mac vlan/voice vlan/ip subnet vlan/protocol vlan) is configured,
then the packet COS value equals COS value of the dynamic VLAN.
 Policy map can only be bound to ingress direction, egress is not supported yet.
 At present, it is not recommended to synchronously use policy map on VLAN and
VLAN’s port.