Reference Guide

Data Center Bridging (DCB) | 279
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 mode on).
• No PFC priority classes are configured (
no pfc priority priority-range)
To configure lossless queues on a port interface, follow these steps:.
FTOS Behavior:
Traffic may be interrupted when you reconfigure PFC no-drop priorities in an input policy or
re-apply the policy to an interface.
FTOS does not support MACsec Bypass Capability (MBC).
Step Task Command Command Mode
Enter INTERFACE Configuration mode. interface type slot/port} CONFIGURATION
Configure the port queues that will still function as
no-drop queues for lossless traffic. For the
dot1p-queue assignments, Refer to Table 15-1.
Maximum number of lossless queues globally
supported on the switch: 2.
Valid values: 0-7. Separate queue values with a
comma; specify a priority range with a dash; for
example: pfc no-drop queues 1,7 or
pfc no-drop queues 2-7
Default: No lossless queues are configured.
pfc no-drop queues
queue-range
INTERFACE