User's Manual

148 CHAPTER 4: DISCOVERING THE NETWORK
however is the hubs/switches being configured in a way that is not
supported by 3Com Network Director or if 3Com Network Director lost
communication with any of the switches when attempting to read
topology information from them. In the latter case additional errors
appear in this report to indicate the loss of communication.
The following devices have one or more ports that have failed
self-test
During the power cycle (reboot), certain 3Com devices run diagnostic
tests against each port and disable any ports that fail these tests. 3Com
Network Director is able to detect this condition and will report it here. It
will also add an event to the event log for this condition. Because the port
has been disabled by the device the topology that 3Com Network
Director deduces may be inaccurate.
3Com Network Director was unable to write to the following
devices, in order to get them to perform operations that could
lead to a more accurate topology detection
At a certain point in the topology process 3Com Network Director may
decide to instruct one device to remote ping another. See“
Remote Poll
Stage (broadcast ARP)” on page 98 and “Remote Poll Stage (directed
pings)” on page 99. It cannot do this if it was previously unable to
determine the write community string for this device – consequently you
should also see a warning relating the write community string for this
device. By not being able to perform the remote poll, the topology that
3Com Network Director depicts may not be accurate.
The following devices have one or more ports that could not be
included in the network topology. These ports are blocked by the
Spanning Tree Protocol. 3Com Network Director was unable to
determine what these ports are connected to.
In order for 3Com Network Director to correctly determine spanning tree
topologies it must correctly discover the devices at both ends of each
blocked spanning tree link. If the IP address ranges discovered prevents
3Com Network Director from determining both devices at the end of a
blocked spanning tree link then 3Com Network Director will be unable to
show the link in the map.