DELL S6000-ON User Manual

PFC Prerequisites and Restrictions

On an S6000 switch, PFC is globally enabled by default, but not applied on specific 802.1p priorities. To 
enable PFC on 802.1p priorities, create a DCB map.

The following prerequisites and restrictions apply when you configure PFC in a DCB map:

• You can enable PFC on a maximum of two priority queues on an interface. Enabling PFC for dot1p 

priorities configures the corresponding port queue as lossless.

• You cannot enable PFC and link-level flow control at the same time on an interface.

Applying a DCB Map on a Port

When you apply a DCB map with PFC enabled on a switch interface, a memory buffer for PFC-enabled 

priority traffic is automatically allocated. The buffer size is allocated according to the number of PFC-

enabled priorities in the assigned map.

To apply a DCB map to an Ethernet port, follow these steps:

Step

Task

Command

Command Mode

1

Enter interface configuration mode on an 

Ethernet port.

interface 
{tengigabitEthernet slot/
port /subport | 
fortygigabitEthernet 
slot/port}

CONFIGURATION

2

Apply the DCB map on the Ethernet port to 

configure it with the PFC and ETS settings in 

the map; for example:

Dell# interface tengigabitEthernet 1/1/1 

Dell(config-if-te-1/1/1)# dcb-map 

SAN_A_dcb_map1 Repeat Steps 1 and 2 to 

apply a DCB map to more than one port.

You cannot apply a DCB map on an interface 

that has been already configured for PFC using 

thepfc priority command or which is 

already configured for lossless queues (pfc 
no-drop queues command).

dcb-map name

INTERFACE

Configuring PFC without a DCB Map

In a network topology that uses the default ETS bandwidth allocation (assigns equal bandwidth to each 
priority), you can also enable PFC for specific dot1p-priorities on individual interfaces without using a 

Data Center Bridging (DCB)

257