Finisar Surveyor, User Manual

Page: 291 / 454

10-87
Expert Features
Network Layer
10
ICMP Time Exceeded
Counter
ICMP Time 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 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
__________________________________________________________________
Problem Description:
An ICMP Time Exceeded message has been sent.
__________________________________________________________________
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.
4. A host may send this message if it cannot reassemble the fragments (due to
missing fragments) on time.
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Recommended Action(s):
1. Check the routing tables of the source.
2. Check the netmask configuration of the source.
3. Check for missing IP fragments.
4. May need to upgrade your router or host.