Finisar Surveyor, User Manual

Page: 307 / 454

10-103
Expert Features
MAC Layer
10
Broadcast/Multicast Storms
Counter
The Broadcast/Multicast Storms counter increments when a change in the number
of total Broadcast/Multicast packets per second exceeds a threshold. Broadcast/
Multicast Storms can be used to monitor extreme peaks in the number of broadcast
and/or multicast messages. A count of all instances where the threshold is reached
displays in the Overview counters of Expert View.
Expert Symptom
Broadcast/Multicast Storm events are automatically logged as expert symptoms.
The
Symptom Summary
field provides information about the rate of change for
broadcast and multicast packets. For example:
Rate of change of Bcast/Mcast Packets=500
The threshold value for this symptom can be changed. The default threshold is a
delta of 400 broadcast/multicast events per second.
Diagnostic Details
__________________________________________________________________
Problem Description:
The broadcast storm expert threshold has been exceeded for this segment, resulting
in a MAC Broadcast Storm symptom.
__________________________________________________________________
Probable Cause(s):
1. The network is overloaded.
2. Variations in application traffic patterns.
3. Heavy Internet usage.
4. Too many broadcast/multicast packets from the switch/bridge.
__________________________________________________________________
Recommended Action(s):
1. Load balance your network.
2. If you see repeated storms, your router or switch may needed upgrading or reconfigur-
ing.