3Com Switch 4800G 24-Port Configuration Manual page 155

Configuring the Storm
Constrain Function on
an Ethernet Port
c
The storm constrain function suppresses packet storm in an Ethernet. With this
function enabled on a port, the system detects the unicast traffic, multicast traffic,
or broadcast traffic passing through the port periodically and takes corresponding
actions (that is, blocking or shutting down the port and sending trap messages
and logs) if the traffic detected exceeds the threshold.
CAUTION: Although the storm suppression function and the storm constrain
function can all be used to control specific type of traffic, they conflict with each
other. So, do not configure the both for an Ethernet port at the same time. For
example, with multicast storm suppression ratio set on an Ethernet port, do not
enable the storm constrain function for multicast traffic on the port. Refer to
"Configuring the Broadcast/Multicast/Unknown Unicast Storm Suppression Ratio
for an Ethernet Port" on page 151 for information about the storm suppression
function.
With the storm constrain function enabled on an Ethernet port, you can specify
the system to act as follows when the traffic detected exceeds the threshold.
Blocking the port. In this case, the port is blocked and thus stops forwarding
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the traffic of this type till the traffic detected is lower than the threshold. Note
that a port blocked by the storm constrain function can still forward other
types of traffic and monitor the blocked traffic.
Shutting down the port. In this case, the port is shut down and stops
■
forwarding all types of traffics. Ports shut down by the storm constrain function
can only be brought up by using the undo shutdown command or disabling
the storm constrain function.
Follow these steps to configure the storm constrain function on an Ethernet port:
To do...
Enter system view
Set the interval for generating
traffic statistics
Enter Ethernet port view
Enable the storm constrain
function and set the lower
threshold and the upper
threshold
Set the action to be taken
when the traffic exceeds the
upper threshold
Specify to send trap messages
when the traffic detected
exceeds the upper threshold
or drops down below the
lower threshold from a point
higher than the upper
threshold
Ethernet Port Configuration
Use the command...
system-view
storm-constrain interval
seconds
interface interface-type
interface-number
storm-constrain
{ broadcast | multicast } pps
max-pps-values
min-pps-values
storm-constrain control
{ block | shutdown }
storm-constrain enable
trap
155
Remarks
-
Optional
Defaults to 10 seconds.
-
Required
By default, the storm constrain
function is disabled.
Optional
By default, the storm constrain
function is disabled.
Optional
By default, the system sends
trap messages when the traffic
detected exceeds the upper
threshold or drops down
below the lower threshold
from a point higher than the
upper threshold.