Reference Guide

Configuring Bandwidth Allocation for DCBx CIN
After you apply an ETS output policy to an interface, if the DCBx version used in your data center network is CIN, you
may need to configure a QoS output policy to overwrite the default CIN bandwidth allocation.
This default setting divides the bandwidth allocated to each port queue equally between the dot1p priority traffic
assigned to the queue.
For more information, refer to Allocating Bandwidth to Queue.
To create a QoS output policy that allocates different amounts of bandwidth to the different traffic types/ dot1p priorities
assigned to a queue and apply the output policy to the interface, follow these steps.
1. Create a QoS output policy.
CONFIGURATION mode
qos-policy-output output-policy-name
The maximum 32 alphanumeric characters.
2. Configure the percentage of bandwidth to allocate to the dot1p priority/queue traffic in the associated L2 class
map.
QoS OUTPUT POLICY mode
bandwidth-percentage percentage
The default is none.
3. Repeat Step 2 to configure bandwidth percentages for other priority queues on the port.
QoS OUTPUT POLICY mode
bandwidth-percentage percentage
4. Exit QoS Output Policy Configuration mode.
QoS OUTPUT POLICY mode
exit
5. Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type slot/port
6. Apply the QoS output policy with the bandwidth percentage for specified priority queues to an egress interface.
INTERFACE mode
service-policy output output-policy-name
Applying DCB Policies in a Switch Stack
You can apply a DCB input policy with PFC configuration to all stacked ports in a switch stack or on a stacked switch.
You can apply different DCB input policies to different stacked switches.
To apply DCB policies in a switch stack, use the following command.
NOTE: Use only 40G ports as stacking ports when you enable DCB. S4820T does not support DCB when you use
10GBaseT ports as stacking ports.
• Apply the specified DCB input policy on all ports of the switch stack or a single stacked switch.
CONFIGURATION mode
dcb-policy input stack-unit {all | stack-unit-id} stack-ports all dcb-input-
policy-name
Entering this command removes all DCB input policies applied to stacked ports.
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