80
To configure WRED on an interface:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view.
interface
interface-type
interface-number
N/A
3.
Enable WRED.
qos wred
[
dscp
|
ip-precedence
]
enable
N/A
4.
Set the WRED exponent
for average queue size
calculation.
qos wred weighting-constant
exponent
Optional.
The default setting is 9.
5.
Set the drop-related
parameters for the
precedence.
qos wred
{
ip-precedence
ip-precedence
|
dscp
dscp-value
}
low-limit
low-limit
high-limit
high-limit
discard-probability
discard-prob
Optional.
By default, the
low-limit
argument is 10, the
high-limit
argument is 30, and the
discard-prob
argument is 10.
6.
Display the WRED
configuration on an
interface/PVC or all
interfaces/PVCs.
display qos wred interface
[
interface-type interface-number
] [
|
{
begin
|
exclude
|
include
}
regular-expression
]
Available in any view.
Configuration example
Network requirements
•
Enable IP precedence-based WRED on interface GigabitEthernet 1/0/1.
•
Set the following parameters for packets with IP precedence 3: lower threshold 20, upper
threshold 40, and drop probability denominator 15.
•
Set the exponential factor for the average queue size calculation to 6.
Configuration procedure
# Enter system view.
<Sysname> system-view
# Enter interface view.
[Sysname] interface gigabitethernet 1/0/1
# Enable IP precedence-based WRED.
[Sysname-GigabitEthernet1/0/1] qos wred ip-precedence enable
# Set the following parameters for packets with IP precedence 3: lower threshold 20, upper threshold
40, and drop probability denominator 15.
[Sysname-GigabitEthernet1/0/1] qos wred ip-precedence 3 low-limit 20 high-limit 40
discard-probability 15
# Set the exponential factor for the average queue size calculation to 6.
[Sysname-GigabitEthernet1/0/1] qos wred weighting-constant 6
Applying a WRED table on an interface
This feature is supported only on SAP modules operating in bridge mode.
A WRED table contains global WRED parameters and supports only the queue-based table. With a
queue-based table, packets are dropped based on the queue when congestion occurs.
