DES-3000 Series Layer 2 Switch CLI Reference Manual
13
T
RAFFIC
C
ONTROL
C
OMMANDS
On a computer network, packets such as Multicast packets and Broadcast packets continually flood the network as normal
procedure. At times, this traffic may increase do to a malicious endstation on the network or a malfunctioning device, such as a
faulty network card. Thus, switch throughput problems will arise and consequently affect the overall performance of the switch
network. To help rectify this packet storm, the Switch will monitor and control the situation.
The packet storm is monitored to determine if too many packets are flooding the network, based on the threshold level provided
by the user. Once a packet storm has been detected, the Switch will drop packets coming into the Switch until the storm has
subsided. This method can be utilized by selecting the
Drop
option of the
Action
field in the window below. The Switch will also
scan and monitor packets coming into the Switch by monitoring the Switch’s chip counter. This method is only viable for
Broadcast and Multicast storms because the chip only has counters for these two types of packets. Once a storm has been detected
(that is, once the packet threshold set below has been exceeded), the Switch will shutdown the port to all incoming traffic with the
exception of STP BPDU packets, for a time period specified using the Countdown field. If this field times out and the packet
storm continues, the port will be placed in a Shutdown Forever mode which will produce a warning message to be sent to the
Trap Receiver. Once in Shutdown Forever mode, the only method of recovering this port is to manually recoup it using the
Port
Configuration
window in the
Administration
folder and selecting the disabled port and returning it to an Enabled status. To
utilize this method of Storm Control, choose the
Shutdown
option of the
Action
field in the window below.
The broadcast storm control commands in the Command Line Interface (CLI) are listed (along with the appropriate parameters) in
the following table.
Command Parameters
config traffic control
[<storm_grouplist> | all] {broadcast [enable | disable] | multicast
[enable | disable] | unicast [enable | disable] | action [drop |
shutdown] | threshold <value 64-1000000> | time_interval <value 5-
30> | countdown [<value 0> | <value 5-30>]}
config traffic control_recover
[<portlist> | all]
config traffic trap
[none | storm_occurred | storm_cleared | both]
show traffic control
{<storm_grouplist>}
Each command is listed, in detail, in the following sections.
config traffic control
Purpose
Used to configure broadcast/multicast traffic control.
Syntax
config traffic control [<storm_grouplist> | all] {broadcast [enable |
disable] | multicast [enable | disable] | unicast [enable | disable] | action
[drop | shutdown] | threshold <value 64-1000000> | time_interval <value
5-30> | countdown [<value 0> | <value 5-30>]}
Description
This command is used to configure traffic control.
Parameters
<storm_grouplist>
−
Used to specify a port or range of ports to be configured
for traffic control.
all
−
Specifies all ports are to be configured for traffic control on the Switch.
broadcast [enable | disable]
−
Enables or disables broadcast storm control.
multicast [enable | disable]
−
Enables or disables multicast storm control.
unicast [enable | disable]
−
Enables or disables unicast traffic control.
action
– Used to configure the action taken when a storm control has been
detected on the Switch. The user has two options:
•
drop
- Utilizes the hardware Traffic Control mechanism, which
means the Switch’s hardware will determine the Packet Storm
based on the Threshold value stated and drop packets until the
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