3Com Switch 7750 Configuration Guide Guide

Ethernet Port Configuration 169
Enabling Flow Control
on a Port
Flow control is enabled on both the local and peer switches. If congestion occurs
on the local switch:
■ The local switch sends a message to notify the peer switch of stopping sending
packets to itself temporarily.
■ The peer switch will stop sending packets to the local switch or reduce the
sending rate temporarily when it receives the message; and vice versa. By this
way, packet loss is avoided and the network service operates normally.
Configuring the Delay of
Reporting Down State
An Ethernet port can be in one of the following physical states: up or down. When
the state of a port changes, the port will report its state change to the system. If
the physical state of a port changes frequently in a short time, the port will send a
large amount of state reports to the system, which occupies plenty of system
resources.
Perform the following configuration to configure the delay of reporting down
state. That is, you can control whether the system can get the port state fast.
When a port is down:
■ The port will not report its state to the system in the specified delay time.
■ The port will report its state to the system after the specified delay expires.
Table 100 Enable flow control on a port
Operation Command Description
Enter system view system-view -
Enable flow control globally flow-control enable
Required
By default, flow control is
disabled globally.
Enter Ethernet port view
interface interface-type
interface-number
-
Enable flow control on the
Ethernet port
flow-control
Required
By default, flow control is
disabled on the port.
Table 101 Configure the delay of reporting down state
Operation Command Description
Enter system view system-view -
Set the delay of reporting
down state for the ports of all
I/O Modules or the specified
I/O Module
port monitor last [ slot
slot-number ] value
Optional
By default, ports are brought
down at the rate of 1.
Enter Ethernet port view
interface interface-type
interface-number
-
Set the delay of reporting
down state for the current
port
port monitor last [ value ]
Optional
By default, the delay of
reporting down state is
related with the configuration
performed in system view.