3com 2948-SFP Plus User Guide

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C
HAPTER 
4: M
ANAGING
 D
EVICE
 S
ECURITY
80
Viewing Broadcast 
Storm
Broadcast Storm limits the amount of Multicast and Broadcast frames 
accepted and forwarded by the device. When Layer 2 frames are 
forwarded, Broadcast and Multicast frames are flooded to all ports on 
the relevant VLAN. This occupies bandwidth, and loads all nodes on all 
ports.
A Broadcast Storm is a result of an excessive amount of broadcast  
messages simultaneously transmitted across a network by a single port. 
Forwarded message responses are heaped onto the network, straining 
network resources or causing the network to time out.
Broadcast Storm is enabled for all Gigabit ports by defining the packet 
type and the rate the packets are transmitted. The system measures the 
incoming Broadcast and Multicast frame rates separately on each port, 
and discards the frames when the rate exceeds a user-defined rate. 
Packet threshold is ignored if Broadcast Storm Control is Disabled.