Surveyor User's Guide

10-77
Expert Features
Network Layer
10
ICMP Network Redirect
Counter
ICMP Network Redirect events are counted in the ICMP Redirect Errors counter
and the ICMP All Errors counter. A count of ICMP redirect errors and 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 redirect errors or for all ICMP errors.
Expert Symptom
ICMP Network Redirect events are automatically logged as expert symptoms. The
Symptom Summary field provides information about the IP addresses involved. For
example:
Use Gateway [206.250.54.61] to reach [206.250.228.69] from
[206.250.228.11]. SA=[206.250.228.11] DA=[206.250.228.69]
Diagnostic Details
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Problem Description:
An ICMP Network Redirect message has been sent.
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Probable Cause(s):
1. If a router has a routing table problem, it may send this message.
2. A router may send this message if according to its (proper) routing tables it finds a
shorter path via a different router.
3. The source may have an incorrectly configured subnet mask.
4. The host (source) may have an old routing table.
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Recommended Action(s):
1. Check the routing tables of the router that this message was generated from.
2. Check the netmask configuration of the source.
3. Ignore this message if the redirect message is valid (no action required).