is below the upper threshold, the switch drops packets at the user-configured drop probability.
When the queue size reaches the upper threshold, all subsequent packets are dropped.
Drop precedence—A parameter used in packet drop. Value 0 represents green packets, 1
represents yellow packets, and 2 represents red packets. Red packets are preferentially dropped.
Drop probability—Drop probability in percentage. A higher value means a higher drop
In a WRED table, drop parameters are configured on a per queue basis because WRED regulates
packets on a per queue basis.
A WRED table can be applied to multiple interfaces. For a WRED table already applied to an interface,
you can modify the values of the WRED table, but you cannot remove the WRED table.
To configure and apply a queue-based WRED table:
Enter system view.
Create a WRED table
and enter its view.
Set other parameters for
the WRED table.
Enter interface view.
Apply the WRED table
to the interface.
Configure a WRED table, set low-limit to 500, high-limit to 2000, and discard-probability to 50 for
yellow packets in queue 1. Apply the WRED table to port GigabitEthernet 1/0/1.
# Enter system view.
# Create a WRED table, and configure the drop parameters.
[Sysname] qos wred queue table queue-table1
[Sysname-wred-table-queue-table1] queue 1 drop-level 1 low-limit 500 high-limit 2000
# Enter port view.
[Sysname] interface gigabitethernet 1/0/1
# Apply the WRED table to port GigabitEthernet 1/0/1.
[Sysname-GigabitEthernet1/0/1] qos wred apply queue-table1
qos wred queue table table-name
queue queue-id [ drop-level drop-level ]
low-limit low-limit high-limit high-limit
[ discard-probability discard-prob ]
interface interface-type interface-number
qos wred apply table-name
By default, low-limit is 100,
high-limit is 1000, and
discard-prob is 10.