Finisar Surveyor - Manual (Page 292)

10-88
Surveyor
User’s Guide
ICMP Time to Live Exceeded
Counter
ICMP Time to Live Exceeded events are counted in the ICMP All Errors counter. A
count of all ICMP errors displays in the
Overview counters of Expert View. A
threshold can be set in Expert Alarms for all ICMP errors.
Expert Symptom
ICMP Time to Live Exceeded events are automatically logged as expert symptoms.
The
Symptom Summary field provides information about the IP addresses involved.
For example:
Sent by Gateway [206.250.228.61] to [206.250.228.11] when
forwarding to Destination [206.250.228.69].
SA=[206.250.228.11] DA=[206.250.228.69]
Diagnostic Details
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Problem Description:
An ICMP Time To Live Exceeded message has been sent.
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Probable Cause(s):
1. A router may send this message if it encounters an IP packet with a TTL value
of 0.
2. The source may have an incorrectly configured subnet mask, causing longer hops.
3. The routing tables may be incorrect on the source.
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Recommended Action(s):
1. Check the routing tables of the source.
2. Check the netmask configuration of the source.