Configuring Congestion Avoidance; Configuring Tail Drop On Egress Queues - Cisco Nexus 9000 Series Configuration Manual

Configuring Congestion Avoidance

Command or Action
Step 8 no bandwidth percent
percentage
Step 9 priority level level
Step 10 queue-limit queue size [dynamic
dynamic threshold]
Configuring Congestion Avoidance
You can configure congestion avoidance with tail drop or WRED features. Both features can be used in egress
policy maps.
WRED and tail drop cannot be configured in the same class.
Note

Configuring Tail Drop on Egress Queues

You can configure tail drop on egress queues by setting thresholds. The device drops any packets that exceed
the thresholds. You can specify a threshold based on the queue size or buffer memory that is used by the
queue.
Cisco Nexus 9000 Series NX-OS Quality of Service Configuration Guide, Release 7.x
102
Purpose
configured with a bandwidth percent. For example, if strict-priority queues take 90
percent of the bandwidth, and you configure 75 percent for a class, the class will
receive 75 percent of the remaining 10 percent of the bandwidth.
Note Before you can successfully allocate bandwidth to the class, you must first
reduce the default bandwidth configuration on class-default and class-fcoe.
(Optional) Removes the bandwidth specification from this class.
(Optional) Specifies the strict priority levels for the Cisco Nexus 9000 Series
switches. These levels can be 1, 2, or 3.
(Optional) Specifies either the static or dynamic shared limit available to the queue
for Cisco Nexus 9000 Series switches. The static queue limit defines the fixed size
to which the queue can grow.
The dynamic queue limit allows the queue's threshold size to be decided depending
on the number of free cells available, in terms of the alpha value.
Cisco Nexus 9200 Series switches only support a class level dynamic
Note
threshold configuration with respect to the alpha value. This means that
all ports in a class share the same alpha value.
Configuring Queuing and Scheduling