148CHAPTER 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.