Version 6 SuperStack 3 Switch 4400 Management Interface Reference Guide

Command Line Interface - physicalInterface ethernet flowControl
http://support.3com.com/infodeli/tools/switches/4400/DHA1720-3AAA08/htmcli/physicalinterfaceethernetflowcontrol.htm[11/15/2010 3:47:48 PM]
Command Line Interface
physicalInterface ethernet flowControl
Enabling and Disabling Flow Control
IEEE Std 802.3-2002 (incorporating 802.3x) flow control minimizes packet loss during
periods of congestion on ports that are operating in full duplex.
You can enable or disable 802.3x flow control for Ethernet ports on the Switch using the
flowControl command on the Ethernet menu.
If auto-negotiation is disabled, then the flowControl command specifies the flow
control of the port. If auto-negotiation is enabled, the flowControl value you specify is
used as the default value when auto-negotiation is disabled or fails.Therefore if auto-
negotiation is enabled, the flowControl command does not show the current flow
control of the port.
During auto-negotiation flow control is determined by the advertised pause bits of
the ports at both ends of the link. The advertised pause bits may be set or cleared using
the flowControl parameter in the
portCapabilities command.
To enable or disable 802.3x flow control for a port:
1. At the Top-level menu, enter:
physicalInterface ethernet flowControl
The following prompt is displayed:
Select Ethernet port (unit:port...,all,?):
2. Enter the number of the unit and port to have 802.3x flow control enabled or
disabled, or enter all for all the ports.
The following prompt is displayed:
Enter new value (on,off) [on]:
3. Enter on or off.
If you are enabling or disabling 802.3x flow control for all the ports, only the ports
which can support 802.3x flow control are changed.
rxOn and txOn are unidirectional flow control commands that may be set up for fiber
Gigabit Ethernet ports. If these command options are displayed, 3Com recommends that
they should only be configured by an experienced Network Administrator from the web
interface.
For 802.3x flow control to operate correctly, it must be enabled at both ends of the
link.
Related Commands
autoMDIX Enabling and Disabling auto MDIX on a port
detail Displaying Detailed Information
portCapabilities Setting the Port Capabilities
portMode Specifying the Speed and Duplex Mode
portState Enabling and Disabling Ports
smartAutosense Enabling/Disabling Smart Autosensing
summary Displaying Port Summary Information