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Installation and Configuration Note for the Catalyst 4000 Layer 3 Services Module
78-10164-03
Configuring Layer 3 QoS
Use the following command syntax to configure QoS scheduling at the system level:
•
value
—The precedence value (0 to 3) is the higher 2 bits of the IP precedence field.
•
weight
—The WRR-scheduling weight (1 to 4). This parameter specifies the weight assigned to
traffic with the given precedence.
To set the precedence back to the default setting for the Catalyst 4000 Layer 3 Services module, use the
no
version of the
qos mapping precedence
command.
Table 13 shows the default WRR weights for IP precedence.
Mapping QoS Scheduling at the Interface Level
Configuring QoS mapping at the interface level overrides the system-level mapping. By using the
qos
mapping precedence
wrr-weight
command, you can assign different WRR-scheduling weights for
traffic destined to any particular interface.
To configure QoS scheduling at the interface level, perform the following tasks in interface
configuration mode:
The QoS commands are applicable to both Gigabit Ethernet and Fast Ethernet interfaces.
To set the precedence back to the system-level default setting for the Catalyst 4000 Layer 3 Services
module, use the
no
version of the
qos mapping precedence
wrr-weight
command.
The destination interface parameter is optional. When the destination interface parameter is not
specified, system-level QoS mapping is configured. If interface-specific QoS mapping is configured for
a certain precedence, it takes priority over the system-level QoS mapping for that precedence.
Configuring Per-Port Traffic Conditioning
This section describes the Cisco IOS commands that you need to configure per-port QoS traffic
conditioning at the interface level. The commands described in this section are unique to Layer 3
switching software. The Catalyst 4000 Layer 3 Services module supports per-port input rate limiting,
output rate limiting, and traffic shaping.
Table 13
Default WRR Weights for IP Precedence
IP Precedence
WRR Weight
0
1
1
2
2
3
3
4
Task
Command
Step 1
Assign a different WRR-scheduling weight for a
particular precedence traffic destined to an interface.
Router (config) #
qos mapping
[
destination
dest-interface
]
precedence
value
wrr-weight
weight
Step 2
Return to privileged EXEC mode.
Router (config) #
Ctrl-Z