The flow-control receive command enables received flow control on an Ethernet interface.
The undo flow-control receive command disables received flow control on an Ethernet interface.
By default, received flow control is disabled on an Ethernet interface.
Ethernet interface view, GE interface view, XGE interface view, MultiGE interface view, 25GE interface view, 40GE interface view, 100GE interface view, port group view
Usage Scenario
Flow control prevents packet loss caused by network congestion. On a unidirectional communication network, after received flow control is enabled on the Ethernet interface at the transmit side using the flow-control receive command and flow control is enabled on the Ethernet interface at the receive side using the flow-control command, if congestion occurs on the device at the receive side, the device sends a message to the device at the transmit side to notify it to stop sending packets. After receiving the message, the device at the transmit side temporarily stops sending packets to the device at the receive side regardless of the interface working rate, preventing congestion. In this case, the device at the transmit side can receive pause frames, but cannot send pause frames; the device at the receive side can receive and send pause frames.
Flow control can be implemented only after flow control is enabled on the peer device.
Flow control, received flow control, flow control auto-negotiation, and received flow control auto-negotiation can be configured on Ethernet interfaces, but cannot be configured together.
The XGE interfaces of the S5720-32C-HI-24S-AC, the first 12 XGE interfaces of the S6720-50L-HI-48S, and the XGE and last eight GE interfaces of the S5720-56C-HI-AC, S5720-56C-PWR-HI-AC, and S5720-56C-PWR-HI-AC1 do not support received flow control.
When an interface works in half-duplex mode, received flow control does not take effect.
In a scenario where Layer 3 services are deployed, enabling received flow control may affect the IP traffic forwarding on the interface. As a result, the interface becomes unavailable. You can run the undo flow-control receive command in the interface view to disable received flow control to recover the interface.