672 Dell PowerConnect 55xx Systems User GuideFILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\DellContax\sources\CxUGQoS.fmD E L L C O N F I D E N T I A L – P R E L I M I N A R Y 1 0 / 3 0 / 1 3 - F O R P R O O F O N LY2 Enter the fields:– Trust Mode — Enable/disable Trust mode.• CoS — Traffic is mapped to queues, based on the VPT field in theVLAN tag, or based on the per-port default CoS value (if there isno VLAN tag on the incoming packet). The mapping of the VPTto queue can be configured in the CoS to Queue page.• DSCP — All IP traffic is mapped to queues, based on the DSCPfield in the IP header. The mapping of the DSCP to queue isconfigured in the DSCP to Queue page.– Always Rewrite DSCP — Check to always rewrite the DSCP values inthe incoming packets with the new values set in the DSCP to Queuepage. When this field is enabled, the switch uses the new DSCPvalues to select the egress queue.Assigning Global Settings Using CLI CommandsThe following table summarizes the CLI commands for configuring fields inthe Global Settings page.The following is an example of the CLI commands:Table 22-8. Global Settings CLI CommandsCLI Command Descriptionqos trust {cos|dscp}no qos trustConfigures the system to either theCoS or DSCP trust state.Use the no form of this command toreturn to the default configuration.qos dscp-mutationno qos dscp-mutationApplies the DSCP Mutation map tosystem DSCP trusted ports.Use the no form of this command torestore the trusted port with noDSCP mutation.console(config)# qos trust dscpconsole(config)# qos dscp-mutation
