Administrator Guide

Table 17. Configuring PFC without a DCB Map (continued)
Step Task Command Command Mode
lossless queues (pfc no-
drop queues
command).
Configuring Lossless Queues
DCB also supports the manual configuration of lossless queues on an interface after you disable PFC mode in a DCB map and
apply the map on 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 802.1p traffic from PFC-enabled peers is automatically mapped to the
no-drop egress queues.
When configuring lossless queues on a port interface, consider the following points:
● By default, no lossless queues are configured on a port.
● A limit of 4 lossless queues are supported on a port. If the number of lossless queues configured exceeds the maximum
supported limit per port (two), an error message is displayed. You must re-configure the value to a smaller number of
queues.
● If you configure lossless queues on an interface that already has a DCB map with PFC enabled (pfc on), an error message is
displayed.
Table 18. Configuring Lossless Queues
Step Task Command Command Mode
1 Enter INTERFACE
Configuration mode.
interface
{tengigabitEthernet
slot/port |
fortygigabitEthernet
slot}
port-number is a port number
from 0 to 23.
CONFIGURATION
2
Open a DCB map and enter
DCB map configuration mode.
dcb-map name
INTERFACE
3
Disable PFC.
no pfc mode on
DCB MAP
4
Return to interface
configuration mode.
exit
DCB MAP
5
Apply the DCB map, created
to disable the PFC operation,
on the interface
dcb-map {name }
INTERFACE
6
Configure the port queues
that still function as no-drop
queues for lossless traffic. For
the dot1p-queue assignments.
The maximum number of
lossless queues globally
supported on a port is 2.
You cannot configure PFC no-
drop queues on an interface
pfc no-drop
queuesqueue-range
INTERFACE
Data Center Bridging (DCB) 253