Cisco IE 4000, Software Configuration Manual

Page: 596 / 1066

592
Configuring QoS
QoS Treatment for Performance-Monitoring Protocols
QoS Queuing for CPU-Generated Traffic
You can use the QoS markings established for the CPU-generated traffic by the cpu traffic qos global configuration
command as packet identifiers in the class-map of an output policy-map to map CPU traffic to class-queues in the output
policy-map on the egress port. You can then use output policy-maps on the egress port to configure queuing and
scheduling for traffic leaving the switch from that port.
If you want to map all CPU-generated traffic to a single class in the output policy-maps without changing the CoS, IP
DSCP, or IP-precedence packet markings, you can use QoS groups for marking CPU-generated traffic.
If you want to map all CPU-generated IP traffic to classes in the output policy maps based on IP-DSCP or IP precedence
without changing those packet markings, you can use a table map:

Configure IP-DSCP or IP precedence marking by using DSCP or precedence as the map from value without a table
map.

Configure IP-DSCP or IP-precedence marking by using DSCP or precedence as the map from value with a table
map, using only the default and copy keywords.
If you want to map all CPU-generated traffic to classes in the output policy maps based on the CoS without changing
the CoS packet markings, you can use the table map:

Configure CoS marking by using CoS as the map from value without a table map.

Configure CoS marking using CoS as the map from value with a table map, using only the default and copy
keywords.
For details about table maps, see Table Maps, page 583 .
Using the cpu traffic qos global configuration command with table mapping, you can configure multiple marking and
queuing policies to work together or independently. You can queue native VLAN traffic based on the CoS markings
configured using the
cpu traffic qos global configuration command.
The cpu traffic qos command specifies the traffic to which it applies: all CPU traffic, only CPU-IP traffic, or only CPU
non-IP traffic. All other traffic is statically mapped to a CPU-default queue on the egress port. All CFM traffic (including
Layer 2 IP SLA probes using CFM) is mapped to classes in the output policy map and queued based on their CoS value.
Note: The switch provides the ability to queue based on the CoS, IP-DSCP, and IP precedence of CPU-generated traffic.
Configuration Guidelines

This feature must be configured globally for a switch; it cannot be configured per-port or per-protocol.

Enter each cpu traffic qos marking action on a separate line.

The cpu traffic qos cos global configuration command configures CoS marking for CPU-generated traffic by using
either a specific CoS value or a table map, but not both. A new configuration overwrites the existing configuration.

The cpu traffic qos dscp global configuration command configures IP-DSCP marking for CPU-generated IP traffic
by using either a specific DSCP value or a table map, but not both. A new configuration overwrites the existing
configuration.

The cpu traffic qos precedence global configuration command configures IP-precedence marking for
CPU-generated IP traffic by using either a specific precedence value or a table map, but not both. A new
configuration overwrites the existing configuration.

The cpu traffic qos dscp and cpu traffic qos precedence global configuration commands are mutually exclusive.
A new configuration overwrites the existing configuration.