Configuring Lossless Queues - Dell S4820T Configuration Manual

Step Task
1 Enter interface configuration mode on an
Ethernet port.
2 Enable PFC on specified priorities. Range:
0-7. Default: None.
Maximum number of lossless queues
supported on an Ethernet port: 2.
Separate priority values with a comma.
Specify a priority range with a dash, for
example: pfc priority 3,5-7
1. You cannot configure PFC using the
pfc priority command on an
interface on which a DCB map has been
applied or which is already configured
for 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 two 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.
Step Task
1 Enter INTERFACE Configuration mode.
Open a DCB map and enter DCB map
2
configuration mode.
274
Command
interface
{tengigabitEthernet slot/
port |
fortygigabitEthernet
slot/port}
pfc priority
priority-range
Command
interface
{tengigabitEthernet
slot/port |
fortygigabitEthernet
slot/port}
dcb-map name
Command Mode
CONFIGURATION
INTERFACE
Command Mode
CONFIGURATION
INTERFACE
Data Center Bridging (DCB)