Flowcontrol (switch port) – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual
Page 373
Switching Commands
Software Reference for x310 Series Switches
C613-50046-01 REV A
AlliedWare Plus
TM
Operating System - Version 5.4.4C
15.11
flowcontrol (switch port)
Use this command to enable flow control, and configure the flow control mode for the
switch port.
Use the no variant of this command to disable flow control for the specified switch port.
Syntax
flowcontrol {send|receive} {off|on}
no flowcontrol
Default
By default, flow control is disabled.
Mode
Interface Configuration
Usage
The flow control mechanism specified by 802.3x is only for full duplex links. It operates by
sending PAUSE frames to the link partner to temporarily suspend transmission on the link
Flow control enables connected Ethernet ports to control traffic rates during congestion
by allowing congested nodes to pause link operation at the other end. If one port
experiences congestion, and cannot receive any more traffic, it notifies the other port to
stop sending until the condition clears. When the local device detects congestion at its
end, it notifies the remote device by sending a pause frame. On receiving a pause frame,
the remote device stops sending data packets, which prevents loss of data packets during
the congestion period.
Flow control is not recommended when running QoS or ACLs, because the complex
queuing, scheduling, and filtering configured by QoS or ACLs may be slowed by applying
flow control.
For half-duplex links, an older form of flow control known as back pressure is supported.
See the related
backpressure command on page 15.2
.
For flow control on async serial (console) ports, see
Examples
Parameter
Description
receive
When the port receives pause frames, it temporarily stops (pauses)
sending traffic.
on
Enable the specified flow control.
off
Disable the specified flow control.
send
When the port is congested (receiving too much traffic), it sends
pause frames to request the other end to temporarily stop (pause)
sending traffic.
awplus#
configure terminal
awplus(config)#
interface port1.0.2
awplus(config-if)#
flowcontrol receive on