3Com SuperStack II 3000 TX, User Manual

Page: 53 / 144

Setting Up the Switch Ports 4-13
■
Unit Default — The port uses Port VLAN Mode or
AutoSelect VLAN Mode depending on the con-
tents of the VLAN Configuration Mode field in
the Unit Setup screen. This is the default setting.
For more information, refer to “Using AutoSelect
VLAN Mode” on page 5-4 .
Broadcast Storm Control The Switch automati-
cally creates an alarm on each of its ports in order
to monitor the level of broadcast traffic on each
port. The Broadcast Storm Control fields allow you
to specify thresholds for the level of broadcast traffic
on a port, and specify an action to take place if the
threshold is exceeded.
Rising Threshold% This field allows you to specify
the percentage of broadcast traffic on the current
port which triggers the alarm for the port. The
default is 20%.
Falling Threshold% This field allows you to specify
the percentage of broadcast traffic on the current
port required to reset the alarm for the port. The
falling threshold prevents the rising threshold
events being triggered continuously. The default is
10%.
Rising Action none / event / disable port /
disable port/notify / blip / blip port/notify
Use this field to specify the action for the alarm to
take when it reaches the rising threshold:
■
none
— no action takes place
■
event — an SNMP trap is generated
■
disable port — the port is disabled
■
disable port/notify — the port is disabled and an
SNMP trap is generated
■
blip — the broadcast and multicast traffic on the
port is blocked for 5 seconds
■
blip port/notify — the broadcast and multicast
traffic on the port is blocked for 5 seconds, and
an SNMP trap is generated
If user defined appears as an option in the Rising
Action field, an unrecognized action has been speci-
fied using a MIB browser. You cannot select this
option.
Falling Action none / event / enable /
event + enable Use this field to specify the action
for the alarm to take when it reaches the falling
threshold:
■
none — no action takes place
■
event — an SNMP trap is generated
■
enable — the port is enabled
■
event + enable — the port is enabled and an
SNMP trap is generated
If user defined appears as an option in the Falling
Action field, an unrecognized action has been speci-
fied using a MIB browser. You cannot select this
option.
You should be aware of the following points when
using Broadcast Storm Control:
■
The Switch takes 5–7 seconds to recognize that a
broadcast storm is occurring.