Reference Guide

Quality of Service 483
Global Settings
Use the Global Settings page to enable Trust on all interfaces on the switch.
This configuration is only active when the QoS mode is Basic. Packets
entering a QoS domain are classified at the edge of the QoS domain.
For more information on setting Trust mode on an interface, see
Interface
Settings
.
To define Trust configuration:
1
Click Quality of Service > QoS Basic Mode > Global Settings in the tree
view to display the
Global Settings page.
2 Enter the fields:
–
Trust Mode — Enable/disable Trust mode.
•
CoS — Traffic is mapped to queues, based on the VPT field in the
VLAN tag, or based on the per-port default CoS value (if there is
no VLAN tag on the incoming packet). The mapping of the VPT
to queue can be configured in the
CoS to Queue page.
•
DSCP — All IP traffic is mapped to queues, based on the DSCP
field in the IP header. The mapping of the DSCP to queue is
configured in the
DSCP to Queue page.
–
Always Rewrite DSCP — Check to always rewrite the DSCP values in
the incoming packets with the new values set in the
DSCP to Queue
page. When this field is enabled, the switch uses the new DSCP
values to select the egress queue.
Assigning Global Settings Using CLI Commands
The following table summarizes the CLI commands for configuring fields in
the
Global Settings page.
Table 22-8. Global Settings CLI Commands
CLI Command Description
qos trust {cos|dscp}
no qos trust
Configures the system to either the
CoS or DSCP trust state.
Use the no form of this command to
return to the default configuration.