User's Manual

316 CHAPTER 7: MONITORING THE NETWORK
Links Without Suitable Data Sources: When you start monitoring
against a link, 3Com Network Director examines the two items at either
end and selects one of them as the data source for the link’s monitoring
information.
However, some items cannot provide suitable information for monitoring
the link. These are as follows:
■ Devices that are not monitored in full monitoring mode.Full
monitoring mode is the only mode that provides enough information
for link monitoring.
■ Non-core devices, such as end stations.These do not provide suitable
information for link monitoring, even if they are monitored in full
monitoring mode.
■ Clouds.Clouds are used to represent unknown portions of the
network or logical entities within the network and do not represent
physical items from which data may be collected.
If neither of the items at either end of a link can provide suitable
monitoring information, 3Com Network Director will not be able to
monitor the connection.
Layer 3 Connections: Layer 3 connections are used within 3Com
Network Director to represent logical connectivity between devices and
subnets.They do not correspond directly to an attribute on a network
device, and so cannot be monitored.
If 3Com Network Director cannot start monitoring on a selected item or
items, you will see an information dialog box like the following: