Reference Guide

Weighted Random Early Detection
Weighted random early detection (WRED) is supported on the Z9000 platform.
Creating WRED Profiles
To create WRED profiles, use the following commands.
1. Create a WRED profile.
CONFIGURATION mode
wred
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 FTOS should apply the profile.
FTOS 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 6–bit field. Dell Networking uses the first 3 bits of this field (DP) to determine the drop precedence.
• DP values of 110 and 100 map to yellow; all other values map to green.
• If you do not configure FTOS 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 FTOS the WRED profile drops.
EXEC Privilege mode
show qos statistics
562