Users Guide

Displaying WRED Drop Statistics
To display WRED drop statistics, use the following command.
• Display the number of packets that the WRED profile drops.
EXEC Privilege mode
show qos statistics
Examples of the show qos statistics Commands
The following shows the show qos statistics output.
Dell# show qos statitstics wred-profile
WInterface Te 0/49
Drop-statistic Dropped Pkts
Green 51624
Yellow 51300
Out of Profile 0
The following shows the show qos statistics output on the port extender.
DELL#show qos statistics peGigE 0/1/1
Interface peGigE 0/1/1
Queue# Matched Pkts
0 0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
DELL#show qos statistics wred-profile peGigE 0/1/1
Interface peGigE 0/1/1
Drop-statistic Dropped Pkts
Green 0
Yellow 0
Out of Profile 0
Displaying egress-queue Statistics
To display the number of transmitted and dropped packets on the egress queues of a WRED-configured
interface, use the following command.
• Display the number of packets and number of bytes on the egress-queue profile.
EXEC Privilege mode
show qos statistics egress-queue
Explicit Congestion Notification
Explicit Congestion Notification (ECN) enhances and extends WRED functionality by marking packets for
later transmission instead of dropping them when a threshold value is exceeded. Use ECN for WRED to
reduce the packet transmission rate in a congested, heavily-loaded network.
While WRED drops packets to indicate congestion, ECN marks packets instead of dropping them when
the average queue length exceeds the threshold value. ECN provides an improved method for
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Quality of Service (QoS)