Configuring Lossless Queues - Dell Force10 S4810P Configuration Manual

A DCB input policy for PFC applied to an interface may become invalid if dot1p-queue mapping is
reconfigured (refer to
situation occurs when the new dot1p-queue assignment exceeds the maximum number (2) of lossless
queues supported globally on the switch. In this case, all PFC configurations received from
PFC-enabled peers are removed and re-synchronized with the peer devices.
Traffic may be interrupted when you reconfigure PFC no-drop priorities in an input policy or re-apply
the policy to an interface.

Configuring Lossless Queues

DCB also supports the manual configuration of lossless queues on an interface when PFC mode is turned
off and priority classes are disabled in a DCB input policy applied to the interface. The configuration of
no-drop queues provides flexibility for ports on which PFC is not needed but lossless traffic should egress
from the interface.
Lossless traffic egresses out the no-drop queues. Ingress dot1p traffic from PFC-enabled interfaces is
automatically mapped to the no-drop egress queues.
Prerequisite: A DCB input policy with PFC configuration is applied to the interface with the following
conditions:
• PFC mode is off (
• No PFC priority classes are configured (
To configure lossless queues on a port interface, follow these steps:
Step Task
1 Enter INTERFACE Configuration mode.
2 Configure the port queues that will still function as
no-drop queues for lossless traffic. For the
dot1p-queue assignments, refer to
Maximum number of lossless queues globally
supported on the switch: 2.
Range: 0-3. Separate queue values with a comma;
specify a priority range with a dash; for example:
no-drop queues 1,3 or
pfc no-drop queues 2-3
Default: No lossless queues are configured.
Create Input Policy Maps
).
no pfc mode on
no pfc priority
Table 13-1.
in Chapter 38, Quality of Service
priority-range).
Command
interface type slot/port
pfc no-drop queues
queue-range
pfc
(QoS)). This
Command Mode
CONFIGURATION
INTERFACE
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