R21xx-HP FlexFabric 11900 Layer 2 LAN Switching Configuration Guide

9
Step Command Remarks
3. Enable PFC for specific
802.1p priorities.
priority-flow-control no-drop
dot1p dot1p-list
By default, PFC is disabled for all
802.1p priorities.
4. Enter Ethernet interface view.
interface interface-type
interface-number
N/A
5. Enable PFC on the interface
through automatic negotiation
or forcibly.
priority-flow-control { auto |
enable }
By default, PFC is disabled.
6. Enable PFC for specific
802.1p priorities.
priority-flow-control no-drop
dot1p dot1p-list
By default, PFC is disabled for all
802.1p priorities.
When you configure PFC, follow these guidelines:
• To make PFC take effect, you must configure PFC in both system view and Ethernet interface view,
and make sure the 802.1p priority list specified in Ethernet interface view is within the 802.1p
priority list specified in system view. When the switch operates in IRF mode, you must enable PFC
on the IRF physical port. For more information about IRF, see IRF Configuration Guide.
• To avoid affecting the normal operations of the IRF function and other protocols, do not configure
PFC for 802.1p priority value 0, 6, or 7.
• To avoid packet loss caused by congestion, you must perform the same PFC configuration on all
ports that the packets pass through.
• To use the PFC feature on a link, ensure that it is enabled on both ends of the link. An interface
processes PFC pause frames only when PFC is enabled on it.
• The relationship between the PFC function and the generic flow control function is shown in Table
2.
Table 2 The relationship between the PFC function and the generic flow control function
flow-control
priority-flow-control
enable
priority-flow-control
no-dro
p
dot1
p
Remarks
Unconfigurable Configured Configured
You cannot enable generic flow
control by using the flow-control
command on a port where PFC is
enabled and PFC is enabled for the
specified 802.1p priority values.
Configured Configurable Unconfigurable
• On a port configured with the
flow-control command, you can
enable PFC, but cannot enable
PFC for specific 802.1p
priorities.
• Enabling both generic flow
control and PFC disables a port
from sending generic or PFC
pause frames to inform its peer
of congestion conditions.
However, the port can still
handle generic and PFC pause
frames from its peer.