H3C S10500X Series Configuration Manual page 26

Table 1 PFC configurations and negotiation results
Local (right)
Peer (below)
enable
auto
Default
Configuration restrictions and guidelines
You can configure PFC in both system view and Ethernet interface view. If you configure PFC in
system view and Ethernet interface view multiple times, the most recent configuration takes effect.
PFC is supported only on interfaces on the following interface modules:
•
SH interface modules.
Only Ethernet interfaces on the following interface modules can be both configured as IRF physical
interfaces and configured with PFC:
•
LSUM1TGS24EC0 interface modules.
•
LSUM1QGS6EC0 interface modules.
Among 100-GE interfaces, only 100-GE interfaces on SH interface modules support PFC.
This feature is not supported on 10-GE interfaces operating at 1000 Mbps on the following interface
modules:
•
FD interface modules: LSUM1GP40TS8FD0, LSUM1TGS24FD0, and LSUM1TGS16FD0
This feature is not supported on 10-GE interfaces operating at 1000 Mbps on the
LSUM1TGS48RSH0 and LSUM1TGS48SH0 interface modules.
To perform PFC on an IRF port, configure PFC on the IRF port and the IRF physical interfaces that
are bound to the IRF port. You must first configure PFC on IRF physical interfaces and then enable
PFC globally. For information about IRF, see Virtual Technologies configuration Guide.
For IRF and other protocols to operate correctly, as a best practice, do not enable PFC for 802.1p
priorities 0, 6, and 7.
To avoid packet loss, apply the same PFC configuration to all interfaces that the packets pass
through.
If you do not enable PFC on an interface, the interface can receive but cannot process PFC pause
frames. To make PFC take effect, you must enable PFC on both ends.
For PFC to operate correctly for an 802.1p priority, make sure the 802.1p priority uses the default
802.1p-local priority map. For more information about the default 802.1p-local priority map, see ACL
and QoS Configuration Guide. To configure the 802.1p-to-local priority map, use the import
command in 802.1p-to-local priority map view. For more information about the import command,
see ACL and QoS Command Reference.
The relationship between PFC and generic flow control is shown in
Table 2 The relationship between PFC and generic flow control
flow-control
Unconfigurable
enable
Enabled
Enabled
Disabled
priority-flow-co
priority-flow-c
ntrol no-drop
ontrol enable
dot1p
Configured Configured
auto
Enabled.
•
Enabled if negotiation
succeeds.
•
Disabled if negotiation fails.
Disabled.
Remarks
After you enable PFC on an interface and for
the specified 802.1p priorities, you cannot
17
Default
Disabled
Disabled
Disabled
Table 2.