HP A5120 EI Series Configuration Guide

5
Configuring link change suppression on an Ethernet interface
An Ethernet interface has two physical link states: up and down. Each time the physical link of an
interface goes up or comes down, the physical layer reports the change to the upper layers, and the
upper layers handle the change, resulting in increased overhead.
To prevent physical link flapping from affecting system performance, configure link change suppression to
delay the reporting of physical link state changes. When the delay expires, the interface reports any
detected change.
Link change suppression does not suppress administrative up or down events. When you shut down or
bring up an interface by using the shutdown or undo shutdown command, the interface reports the event
to the upper layers immediately.
On an A5120 EI switch, you can configure link-down suppression or link-up suppression, but not both.
Link-down suppression enables an interface to suppress link-down events and start a delay timer each time
the physical link goes down. During this delay, the interface does not report the link-down event, and the
display interface brief or display interface command displays the interface state as UP. If the physical link
is still down when the timer expires, the interface reports the link-down event to the upper layers.
Link-up suppression enables an interface to suppress link-up events and start a delay timer each time the
physical link goes up. During this delay, the interface does not report the link-up event, and the display
interface brief or display interface command displays the interface state as DOWN. If the physical link is
still up when the timer expires, the interface reports the link-up event to the upper layers.
Configuring link-down suppression
Follow these steps to enable an Ethernet interface to suppress link-down events:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter Ethernet interface view
interface interface-type
interface-number
—
Set a link-down suppression
interval
link-delay delay-time
Required
Link-down suppression is disabled by
default.
Configuring link-up suppression
Follow these steps to configure link-up suppression on an Ethernet interface:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter Ethernet interface view
interface interface-type interface-
number
—
Set a link-up suppression interval
link-delay delay-time mode up
Required
Link-up suppression is disabled by
default.

HP A5120 EI Series Specifications

General

Uplink Ports	4 x SFP
Stacking	No
Management	CLI, Web, SNMP
Routing Protocols	RIP, OSPF
Power Supply	AC
MAC Address Table Size	16K
Dimensions	440 x 430 x 44 mm
Operating Temperature	0°C to 45°C
Operating Humidity	10% to 90% non-condensing
Model	HP A5120-24G EI Switch (JG234A)
VLANs	4094