User's Manual

Key Concepts 321
SNMP Trap-Based Events
SNMP traps that are received by 3Com Network Director are processed
and then used to generate SNMP trap-based events. SNMP trap-based
events are indicated clearly in the Events window with their description
being preceded by Trap:, or preceded by RMON alarm: if the SNMP trap
was generated in response to an RMON alarm.
RMON (Remote network MONitoring) is a set of IETF standards that
define SNMP MIBs that can be used for monitoring various aspects of a
networks’ performance, such as throughput, conversations that have
occurred on the network, response times and so on.
The standards define an alarm mechanism that allows a device to send
SNMP traps when any of the attributes that it maintains statistics on
reaches a certain state, in much the same way as a monitor generates an
event when the monitor enters the warning or high states. For example, a
device may be configured with an RMON alarm that is started when the
packet rate through a particular port reaches a certain level.
For more information on SNMP traps, see “
Controlling SNMP Trap
Filtering” on page 354.
3Com Network Director Internal Events
When you perform certain operations within 3Com Network Director,
such as an Agent Upgrade or Backup, an event will be generated when
the operation has completed. These events provide an audit trail of the
operations that you have applied to your network.
In addition, events are generated when you open, close and create new
maps. These are generated so that you can easily identify whether a
period during which no events were logged is due to the network being
in a stable state or due to 3Com Network Director not being active.
Event Severities Each logged event has a severity associated with it that is used to indicate
the perceived impact of the event on your network. There are five event
severities, in order of increasing severity these are: info, warning, high,
critical and recurring.
Information Severity
The information, or info, severity is used for any event that does not, as
far as 3Com Network Director can determine, have any negative impact
upon your network. This includes such occurrences as maps being