Dell 9.7(0.0) Plumbing Product User Manual


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Create a QoS Policy
There are two types of QoS policies — input and output.
Input QoS policies regulate Layer 3 and Layer 2 ingress traffic. The regulation mechanisms for input QoS
policies are rate policing and setting priority values.
Layer 3 — QoS input policies allow you to rate police and set a DSCP or dot1p value. In addition, you
can configure a drop precedence for incoming packets based on their DSCP value by using a DSCP
color map. For more information, see DSCP Color Maps.
Layer 2 — QoS input policies allow you to rate police and set a dot1p value.
Output QoS policies regulate egress traffic. The regulation mechanisms for output QoS policies are
bandwidth percentage, scheduler strict, rate shaping and WRED.
NOTE: When changing a "service-queue" configuration in a QoS policy map, all QoS rules are
deleted and re-added automatically to ensure that the order of the rules is maintained. As a result,
the Matched Packets value shown in the show qos statistics command is reset.
NOTE: To avoid issues misconfiguration causes, Dell Networking recommends configuring either
DCBX or Egress QoS features, but not both simultaneously. If you enable both DCBX and Egress
QoS at the same time, the DCBX configuration is applied and unexpected behavior occurs on the
Egress QoS.
Creating an Input QoS Policy
To create an input QoS policy, use the following steps.
1. Create a Layer 3 input QoS policy.
CONFIGURATION mode
qos-policy-input
Create a Layer 2 input QoS policy by specifying the keyword layer2 after the qos-policy-input
command.
2. After you create an input QoS policy, do one or more of the following:
Configuring Policy-Based Rate Policing
Setting a DSCP Value for Egress Packets
Setting a dot1p Value for Egress Packets
Configuring Policy-Based Rate Policing
To configure policy-based rate policing, use the following command.
Configure rate police ingress traffic.
QOS-POLICY-IN mode
rate-police
Setting a DSCP Value for Egress Packets
In an input QoS policy, you can set a DSCP value for egress packets based on ingress QoS classification.
The 6–bits that are used for DSCP are also used to identify the queue in which traffic is buffered. When
you set a DSCP value, Dell Networking OS displays an informational message advising you of the queue
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Quality of Service (QoS)