Finisar Surveyor - Manual (Page 248)

10-44
Surveyor
User’s Guide
Non Responsive Station
Counter
Non Responsive Station is a counter of all non-responsive stations over a period of
time per segment. A non-responsive station is defined as successive TCP/IP
retransmissions over the same connection that are greater than a threshold value. A
count of all non-responsive stations displays in the
Overview counters of Expert
View. A threshold for the number of Non Responsive Station events can be set in
Expert Alarms.
Expert Analysis
Non Responsive Station events are automatically logged as expert analyses. The
Symptom Summary field provides the IP address of the non-responsive station. For
example:
Station [206.250.228.11] not responding
The threshold value for the number of retransmissions can be changed. The default
threshold is 3 successive retransmissions.
Diagnostic Details
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Problem Description:
The threshold set for consecutive retransmissions has been exceeded.
This resulted in a Non Responsive Station symptom.
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Probable Cause(s):
1. An ACK sent by the receiver was lost.
2. The network is overloaded.
3. The path to the receiving station has long delays.
4. There may be a problem with the receiver’s TCP/IP stack.
5. There may be an overloaded switch or router.
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Recommended Action(s):
1. Load balance your network.
2. If you see repeated delays and too many retransmissions, your router or switch may
need upgrading.