Priority Mapping Results Are Incorrect
Common Causes
- On the outbound interface, packets do not enter queues corresponding to priorities of packets.
- The priority types trusted by the inbound and outbound interfaces do not meet service requirements.
- The priority mappings configured in the DiffServ domains bound to the inbound and outbound interfaces do not meet service requirements.
- There are configurations affecting priority mapping on the inbound and outbound interfaces.
Procedure
- Check whether packets enter the correct queues on the outbound interface.
Run the display qos queue statistics interface interface-type interface-number command to check whether packets enter the correct queues on the outbound interface.
- If packets enter incorrect queues, locate the fault. For details, see Packets Enter Incorrect Queues.
- If packets enter the correct queues, go to step 2.
- Check whether the priority mapping configuration in the DiffServ domain bound to the VLAN or VLANIF interface is correct.
Run the display this command in the VLAN or VLANIF interface view to check whether the trust upstream command is configured. If this command is not configured, the system trusts the DiffServ domain default by default.
Run the display diffserv domain ds-domain-name command to check whether the mappings between PHBs/colors and packet priorities are correct.
- If the priority mappings are incorrect, run the ip-dscp-outbound, mpls-exp-outbound, or 8021p-outbound command to configure the mappings between PHBs/colors and packet priorities.
- If the priority mappings are correct, go to step 3.
- Check whether there are configurations affecting priority mapping on the inbound and outbound interfaces.
The system does not map PHBs and colors of outgoing packets to DSCP priorities if the qos phb marking dscp enable command is not configured in the system view or if the qos phb marking 8021p disable command is configured in the system view.
Run the display this command in the system view to check for configurations affecting priority mapping.
- If such configurations are found, delete or modify them.
- If such configurations are not found, go to step 4.
- Check whether any configurations are affecting packet queuing in the VLAN to which the packets belong.
The following configurations affect packet queuing in the VLAN to which the packets belong:
- If the trust upstream none command is configured, the system does not perform priority mapping for incoming and outgoing packets in the VLAN. Instead, the system sends packets to queues based on interface priorities.
- If the packets match a traffic policy that is applied to the inbound direction (using the traffic-policy command) and contains a remark local-precedence traffic behavior, the system sends packets to queues based on the re-marked priorities.
- If the packets match a traffic policy that is applied to the inbound direction (using the traffic-policy command) and contains a remark 8021p or remark dscp traffic behavior, the system maps the re-marked priorities of packets to local priorities and sends the packets to queues based on the mapped local priorities.
Run the display this command in the VLAN view to check for the preceding configurations. If such configurations are found, delete or modify them.