Applying A Dcb Map On A Port; Configuring Pfc Without A Dcb Map - Dell S4820T Configuration Manual

As a result, PFC and lossless port queues are disabled on 802.1p priorities, and all priorities are
mapped to the same priority queue and equally share the port bandwidth.
• To change the ETS bandwidth allocation configured for a priority group in a DCB map, do not modify
the existing DCB map configuration. Instead, first create a new DCB map with the desired PFC and
ETS settings, and apply the new map to the interfaces to override the previous DCB map settings.
Then, delete the original dot1p priority-priority group mapping.
If you delete the dot1p priority-priority group mapping (no priority pgid command) before you
apply the new DCB map, the default PFC and ETS parameters are applied on the interfaces. This
change may create a DCB mismatch with peer DCB devices and interrupt network operation.

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
Enter interface configuration mode on an
1
Ethernet port.
Apply the DCB map on the Ethernet port to
2
configure it with the PFC and ETS settings in
the map; for example:
Dell# interface tengigabitEthernet 1/1
Dell(config-if-te-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).

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
DCB map. This type of DCB configuration is useful on interfaces that require PFC for lossless traffic, but
do not transmit converged Ethernet traffic.
Data Center Bridging (DCB)
Command
interface
{tengigabitEthernet slot/
port |
fortygigabitEthernet
slot/port}
dcb-map name
Command Mode
CONFIGURATION
INTERFACE
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