Surveyor User's Guide

10-72
Surveyor
User’s Guide
ICMP Host Redirect
Counter
ICMP Host 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 Host 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 Host 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).