Configuring Generic Flow Control On An Ethernet Interface - H3C S6850 Series Configuration Manual

If the configured value is greater than 64 but not an integer multiple of 64, the integer
multiple of 64 that is greater than and closest to the configured value takes effect.
For the suppression threshold that takes effect, see the prompt on the device.
•
Set the same type of thresholds for each interface.
Procedure
1. Enter system view.
system-view
2. Enter Ethernet interface view.
interface interface-type interface-number
3. Enable broadcast suppression and set the broadcast suppression threshold.
broadcast-suppression { ratio | pps max-pps | kbps max-kbps }
By default, broadcast suppression is disabled.
4. Enable multicast suppression and set the multicast suppression threshold.
multicast-suppression { ratio | pps max-pps | kbps max-kbps }
[ unknown ]
By default, multicast suppression is disabled.
5. Enable unknown unicast suppression and set the unknown unicast suppression threshold.
unicast-suppression { ratio | pps max-pps | kbps max-kbps }
By default, unknown unicast suppression is disabled.

Configuring generic flow control on an Ethernet interface

About generic flow control
To avoid dropping packets on a link, you can enable generic flow control at both ends of the link.
When traffic congestion occurs at the receiving end, the receiving end sends a flow control (Pause)
frame to ask the sending end to suspend sending packets. Generic flow control includes the
following types:
•
TxRx-mode generic flow control—Enabled by using the flow-control command. With
TxRx-mode generic flow control enabled, an interface can both send and receive flow control
frames:
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 packets
to its peer.
•
Rx-mode generic flow control—Enabled by using the flow-control receive enable
command. With Rx-mode generic flow control enabled, an interface can receive flow control
frames, 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 packets
to its peer.
To handle unidirectional traffic congestion on a link, configure the flow-control receive
enable command at one end and the flow-control command at the other end. To enable both
ends of a link to handle traffic congestion, configure the flow-control command at both ends.
Procedure
1. Enter system view.
system-view
2. Enter Ethernet interface view.
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