H3C Technologies H3C S12500-X Series Switches - Manual (Page 19)

8
To configure PFC on an Ethernet interface:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter Ethernet interface view. interface interface-type
interface-number
N/A
3. Enable PFC on the interface
through automatic negotiation
or forcibly.
priority-flow-control { auto |
enable }
By default, PFC is disabled.
4. 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 perform PFC on a network port of an IRF member device, configure PFC on both the network port
and the IRF physical ports. For information about IRF, see IRF configuration Guide.
• To ensure correct operations of IRF and other protocols, H3C recommends not enabling PFC for
802.1p priorities 0, 6, and 7.
• Perform the same PFC configuration on all ports that traffic travels through.
• A port can receive PFC pause frames whether or not PFC is enabled on the port. However, only a
port with PFC enabled can process PFC pause frames. To make PFC take effect, make sure PFC is
enabled on both the local end and the peer end.
The relationship between the PFC function and the generic flow control function is shown in Table 1 .
Table 1 The relationship between the PFC function and the generic flow control function
flow-control
priority-flo
w-control
enable
priority-flow-contr
ol no-drop dot1p
Remarks
Unconfigurable Configured Configured
You cannot enable 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 you
cannot enable PFC for specific 802.1p
priorities.
• Enabling both generic flow control and PFC on
a port disables the port from sending common
or PFC pause frames to inform the peer of
congestion conditions. However, the port can
still handle common and PFC pause frames
from the peer.