Linksys DES-3028/DES-3028P/DES-3052/DES-3052P 用户手册

下载
页码 250
DES-3028 DES-3028P DES-3052 DES-3052P  Layer 2 Fast Ethernet Switch CLI Reference Manual 
13 
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 64-1000000> | time_interval <sec 5-30> | 
countdown [<minutes 0>| <minute 5-30>]} 
show traffic control 
{<portlist>} 
config traffic trap 
[none | storm_occurred | storm_cleared | both] 
Each command is listed, in detail, in the following sections. 
config traffic control 
Purpose 
Used to configure broadcast/multicast/dlf packet storm control. The 
software mechanism is provided to monitor the traffic rate in addition to 
the hardware storm control mechanism previously provided. 
Syntax 
config traffic control [<portlist> | all] {broadcast [enable | disable] | 
multicast [enable | disable] | dlf [enable | disable] | action [drop | 
shutdown] | threshold <value 64-1000000> | time_interval <sec 5-30> 
| countdown [<minutes 0> | <minute 5-30>]} 
Description 
This command is used to configure broadcast/multicast/dlf storm control. 
By adding the new software traffic control mechanism, the user can now 
use both a hardware and software mechanism, the latter of which will now 
provide shutdown, recovery and trap notification functions for the Switch. 
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 
 
87