Overview - Allied Telesis AT-GS950/24 User Manual

Chapter 14: Storm Control

Overview

208
The features available in the AT-S109 Version 1.1.0 Management
software allow you to limit Ethernet traffic within your switch based on
specific criteria. You can use Storm Control to limit the bandwidth of
various types of Ethernet packets. With Ingress and Egress Rate Limiting,
you can limit the traffic volume at the input or output ports respectively.
The Storm Control feature allows you regulate the reception rate of
broadcast, multicast, and destination lookup failure (DLF) packets. The
AT-S109 Version 1.1.0 Management software allows you to set separate
limits for each port beyond which each of the different packet types are
discarded. Each setting can be configured on individual ports or on all of
the ports of the AT-GS950/24 switch. Traffic is measured in packets per
second. See the following definitions for more information about these
settings.
Destination Lookup Failure - The Destination Lookup Failure
(DLF) setting is concerned with comparing the destination MAC
address of a packet received by the switch to the forwarding
database. When the AT-GS950/24 switch receives a packet, it
scans the forwarding database and looks for a match to the
destination MAC address in the received packet. If the MAC
address is not present, then the packet is flooded according to the
VLAN rules. By default, this setting is disabled on the switch which
means that all DLF packets are automatically forwarded according
to the VLAN rules.
Broadcast Setting - The broadcast setting applies to allowing or
denying broadcast packets on each port.
Multicast Setting - The multicast setting applies to allowing or
denying multicast packets on each port.
Threshold Level - In regards to Bandwidth control, the threshold
level is the number of DLF, broadcast, and multicast packets that
are sent by or received from a port. This value is measured in
packets per second. You can set the threshold level to low,
medium, or high.
Note
The packet sizes affected by this threshold level can vary in size
from 64 Bytes to 1024 Bytes.