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When Broadcast, Multicast, or Unknown Unicast frames are received, they are duplicated, and
a copy is sent to all possible egress ports. This means that in practice they are sent to all ports
belonging to the relevant VLAN. In this way, one ingress frame is turned into many, creating
the potential for a traffic storm.
Storm protection enables you to limit the number of frames entering the device and to define
the types of frames that are counted towards this limit.
When the rate of Broadcast, Multicast, or Unknown Unicast frames is higher than the user-
defined threshold, frames received beyond the threshold are discarded.
Storm Control
To define Storm Control:
Click Security > Storm Control > Storm Control Settings.
Select a port and click Edit.
Enter the parameters.
•
Interface—Select the port for which storm control is enabled.
Unicast Storm Control
•
Storm Control State—Select to enable Storm Control for Unicast packets.
•
Rate Threshold—Enter the maximum rate at which unknown packets can be
forwarded. This value can be entered by Kbits/sec or By percentage of the total
available bandwidth.
•
Trap on Storm—Select to send a trap when a storm occurs on a port. If this is not
selected, the trap is not sent.
•
Shutdown on Storm—Select to shutdown a port when a storm occurs on the port. If
this is not selected extra traffic is discarded.
Multicast Storm Control
•
Storm Control State—Select to enable Storm Control for Multicast packets.
•
Multicast Type—Select one of the following types of Multicast packets on which to
implement storm control:
-
All—Enables storm control on all Multicast packets on the port.
-
Registered Multicast—Enables storm control only on registered Multicast addresses
on the port.
Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x
Security
Storm Control