Service Manual

Table Of Contents
You can create a custom WRED profile or use one of the five pre-defined profiles.
Enabling and Disabling WRED Globally
By default, WRED is enabled on the system. You can disable or reenable WRED manually using a single command. Follow these
steps to disable or enable WRED in Dell EMC Networking OS.
Enable WRED
CONFIGURATION mode
wred enable
Disable WRED
CONFIGURATION mode
no wred enable
NOTE: If you disable WRED globally, the system accepts any WRED profile you apply to traffic. But the changes do not
take effect until you enable WRED globally.
Creating WRED Profiles
To create WRED profiles, use the following commands.
1. Create a WRED profile.
CONFIGURATION mode
wred-profile
2. Specify the minimum and maximum threshold values.
WRED mode
threshold
Applying a WRED Profile to Traffic
After you create a WRED profile, you must specify to which traffic Dell EMC Networking OS should apply the profile.
Dell EMC Networking OS assigns a color (also called drop precedence) red, yellow, or green to each packet based on it
DSCP value before queuing it.
DSCP is a 6bit field. Dell EMC Networking uses the first three bits (LSB) of this field (DP) to determine the drop precedence.
DP values of 110 and 100, 101 map to yellow; all other values map to green.
If you do not configure Dell EMC Networking OS to honor DSCP values on ingress (refer to Honoring DSCP Values on
Ingress Packets), all traffic defaults to green drop precedence.
Assign a WRED profile to either yellow or green traffic.
QOS-POLICY-OUT mode
wred
Displaying Default and Configured WRED Profiles
To display the default and configured WRED profiles, use the following command.
Display default and configured WRED profiles and their threshold values.
EXEC mode
show qos wred-profile
Displaying WRED Drop Statistics
To display WRED drop statistics, use the following command.
Display the number of packets Dell EMC Networking OS the WRED profile drops.
Quality of Service (QoS)
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