xStack DGS-3612G Layer 3 Gigabit Ethernet Managed Switch CLI Manual
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B
ROADCAST
S
TORM
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 [<portlist> | all] {broadcast [enable | disable] | multicast [enable |
disable] | dlf [enable | disable] | action [drop | shutdown] |
threshold <value 0-255000> | countdown [<value 0> | <value 5-
30>] | time_interval <value 5-30>}
config traffic
control_recover
[<portlist> | all]
config traffic trap
[none | storm_occurred | storm_cleared | both]
show traffic control
{<portlist>}
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 [<portlist> | all] broadcast [enable | disable] |
multicast [enable | disable] | dlf [enable | disable] | action [drop |
shutdown] | threshold <value 0-255000> | countdown [<value 0> | <value
5-30>] | time_interval <value 5-30>}
Description
This command is used to configure traffic control.
Parameters
<portlist>
−
Used to specify a 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.
dlf [enable | disable]
−
Enables or disables dlf 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
issue is resolved.
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