H3C S7500E-XS Series Interface Configuration Manual

Also see for S7500E-XS Series: Evb configuration guide Installation guide Faq Command reference Command reference

H3C S7500E-XS Series Interface Configuration Manual Manual pdf 16 page image

9{ When congestion occurs, the interface sends a flow control frame to its peer.{ When the interface receives a flow control frame from its peer, it suspends sending packetsto its peer.• Rx-mode generic flow control—Enabled by using the flow-control receive enablecommand. With Rx-mode generic flow control enabled, an interface can receive flow controlframes, but it cannot send flow control frames:{ When congestion occurs, the interface cannot send flow control frames to its peer.{ When the interface receives a flow control frame from its peer, it suspends sending packetsto its peer.To handle unidirectional traffic congestion on a link, configure the flow-control receive enablecommand at one end and the flow-control command at the other end. To enable both ends of a linkto handle traffic congestion, configure the flow-control command at both ends.To enable generic flow control on an Ethernet interface:Step Command Remarks1. Enter system view. system-view N/A2. Enter Ethernet interfaceview.interface interface-typeinterface-number N/A3. Enable generic flowcontrol.• Enable TxRx-modegeneric flow control:flow-control• Enable Rx-mode genericflow control:flow-control receiveenableBy default, generic flow control isdisabled on an Ethernet interface.Configuring PFC on an Ethernet interfaceWhen congestion occurs in the network, the local device notifies the peer to stop sending packetscarrying the specified 802.1p priority if all of the following conditions exist:• Both the local end and the remote end have PFC enabled.• Both the local end and the remote end have the priority-flow-control no-drop dot1pcommand configured.• The specified 802.1p priority is in the 802.1p priority list specified by the dot1p-list argument.• The local end receives a packet carrying the specified 802.1p priority.The state of the PFC feature is determined by the PFC configuration on the local end and on the peerend. In Table 1:• The first row lists the PFC configuration on the local interface.• The first column lists the PFC configuration on the peer.• The Enabled and Disabled fields in other cells are possible negotiation results.Make sure all interfaces that a data flow passes through have the same PFC configuration.Table 1 PFC configurations and negotiation resultsLocal (right)Peer (below) enable auto Defaultenable Enabled Enabled. Disabled