xStack DES-3500 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual
68
Traffic Control Settings
Storm Type
Select the type of Storm Type to detect, either Broadcast Multicast or DLF. Once selected , use the
pull-down menu to enable or disable this storm detection.
Action
Select the method of traffic Control from the pull down menu. The choices are:
shutdown
– Utilizes the Switch’s software Traffic Control mechanism to determine the Packet Storm
occurring. Once detected, the port will deny all incoming traffic to the port except STP BPDU
packets, which are essential in keeping the Spanning Tree operational on the Switch. If the
Countdown timer has expired and yet the Packet Storm continues, the port will be placed in
Shutdown Forever mode and is no longer operational until the user manually resets the port using
the
Port Configuration
window in the
Configuration
folder and selecting the disabled port and
returning it to an Enabled status. Choosing this option obligates the user to configure the Interval
setting as well, which will provide packet count samplings from the Switch’s chip to determine if a
Packet Storm is occurring.
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.
Group List
Select the ports to be manually recovered from the Shutdown state.
Threshold
Specifies the maximum number of packets per second that will trigger the Traffic Control function to
commence. The configurable threshold range is from 0-255000 with a default setting of 128000.
Time Interval
The Interval will set the time between Multicast and Broadcast packet counts sent from the Switch’s
chip to the Traffic Control function. These packet counts are the determining factor in deciding when
incoming packets exceed the Threshold value. The Interval may be set between 5 and 30 seconds
with the default setting of 5 seconds.
Count Down
The Count Down timer is set to determine the amount of time, in minutes, that the Switch will wait
before shutting down the port that is experiencing a traffic storm. This parameter is only useful for
ports configured as
Shutdown
in their
Action
field and therefore will not operate for Hardware based
Traffic Control implementations. The possible time settings for this field are 0, 5-30 minutes. 0 is the
default setting for this field and 0 will denote that the port will immediately shutdown.
Click
Apply
to implement the settings made.
NOTE:
Traffic Control cannot be implemented on ports that are set for Link Aggregation (Port Trunking).
NOTE:
Ports that are in the Shutdown forever mode will be seen as Discarding in Spanning Tree
windows and implementations though these ports will still be forwarding BPDUs to the Switch’s CPU.
NOTE:
Ports that are in Shutdown Forever mode will be seen as link down in all windows and screens
until the user recovers these ports.
NOTE:
When configuring the traffic storm settings, remember that when it is configured for
shutdown
,
the Group List will refer to individual ports. Yet, when the traffic control is configured for
drop
, the group
list refers to groups of ports. (Ex – 1 refers to ports 1 through 8, 2 refers to ports 9-16…)
The group list settings for drop are as follows:
Group 1 - Inclusive for ports 1-8.
Group 2 - Inclusive for ports 9-16.
Group 3 - Inclusive for ports 17-24.
Group 4 - Inclusive for ports 9-16 (DES-3550). Inclusive for Gigabit port 25 (DES-3526).
Group 5 - Inclusive for ports 33-40 (DES-3550). Inclusive for Gigabit port 26 (DES-3526).
Group 6 - Inclusive for ports 41-48 (DES-3550 only).
Group 7 - Inclusive for Gigabit port 49 (DES-3550 only).
Group 8 - Inclusive for Gigabit port 50 (DES-3550 only).
