8When you configure PFC, follow these guidelines:• To perform PFC on a network port of an IRF member device, configure PFC on both the network portand 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 for802.1p priorities 0, 6, and 7.• Perform the same PFC configuration on all ports that traffic travels through.• A port can receive PFC pause frames regardless of whether PFC is enabled on the port. However,only a port with PFC enabled can process PFC pause frames. To make PFC take effect, make surePFC is enabled on both the local end and the peer end.The relationship between the PFC feature and the generic flow control feature is shown in Table 1.Table 1 The relationship between the PFC feature and the generic flow control featureflow-controlpriority-flow-controlenablepriority-flow-control no-drop dot1p RemarksUnconfigurable Configured ConfiguredYou cannot enable flow control by using theflow-control command on a port where PFC isenabled and PFC is enabled for the specified802.1p priority values.Configured Configurable Unconfigurable• On a port configured with the flow-controlcommand, you can enable PFC, but youcannot enable PFC for specific 802.1ppriorities.• Enabling both generic flow control and PFC ona port disables the port from sending commonor PFC pause frames. However, the port canstill handle common and PFC pause framesfrom the peer.Enabling energy saving features on an Ethernet interfaceEnabling auto power-down on an Ethernet interfaceIMPORTANT:Fiber ports do not support this feature.With the auto power-down feature, if an interface has been down for a certain period of time, thefollowing events occur:• The device automatically stops supplying power to the interface.• The interface enters the power save mode.The time period depends on the chip specifications and is not configurable. When the interface goes up,the device automatically restores power supply to the interface and the interface enters its normal state.This feature is applicable to only S5820V2-54QS-GE switches.To enable auto power-down on an Ethernet interface:
