308 CHAPTER 28: QO S CONFIGURATIONConfiguring to Trust the802.1p Precedence ofthe Received PacketsYou can configure the switch to trust the 802.1p precedence of the receivedpackets. In this case, the priority of the receiving port is not used as the 802.1pprecedence of the received packet.Configuration prerequisitesTo trust the 802.1p precedence of the received packets is determined.Configuration procedureConfiguration example# Configure the switch to trust the 802.1p precedence of the received packets.<4210> system-view[4210] priority trustConfiguring PriorityTrust ModeRefer to section 1.2.3 "Priority Trust Mode" for introduction to priority trustmode.Configuration prerequisitesThe priority trust mode to be adopted is determined.Configuration procedureConfiguration example# Configure the switch to trust the DSCP precedence of the received packets.<4210> system-view[4210] priority-trust dscpTable 228 Configure to trust the 802.1p precedence of the received packetsOperation Command DescriptionEnter system view system-view -Configure to trust the802.1p precedence of thereceived packetspriority trust RequiredBy default, for a packet with an 802.1q tagheader, the priority of the receiving port isused as the 802.1p precedence of thereceived packets.Table 229 Configure the priority trust modeOperation Command DescriptionEnter system view system-view -Configure the prioritytrust modepriority-trust { cos |dscp | ip-precedence }RequiredBy default, the switch trusts the 802.1pprecedence of the received packets. In thiscase, the switch obtains the localprecedence by looking up the 802.1pprecedence in the802.1p-precedence-to-local-precedencemapping table and then assigns the localprecedence to the packet.
