3com corebuilder 10002211 Manuel D’Utilisation

You can associate an alarm with the high threshold, the low threshold, or 
both. The actions taken because of an alarm depend on the network 
management application. 

The RMON hysteresis mechanism provides a way to prevent small 
fluctuations in counter values from causing alarms. This mechanism 
generates an alarm only under the following conditions:

■

The counter value exceeds the high threshold after previously falling below 
the low threshold. (An alarm does not occur if the value has not fallen 
below the low threshold before rising above the high threshold.)

■

The counter value exceeds the low threshold after previously exceeding the 
high threshold. (An alarm does not occur if the value has not risen above 
the high threshold before falling below the low threshold.)

, for example, an alarm occurs the first time the counter 

exceeds the high threshold, but not at the second time. At the first instance, 
the counter is rising from below the low threshold, while in the second 
instance, it is not.

The Host Group records statistics for each host, denoted by the host’s 
physical MAC address, detected on the network. The information 
available from this group for each discovered host includes:

■

Number of received packets

■

Number of transmitted packets

■

Number of received octets

■

Number of transmitted octets

■

Number of transmitted broadcast packets

■

Number of transmitted multicast packets

■

hostTimeTable that provides all these statistics in a format indexed by the 
relative order in which the host was discovered. Host Group adds new hosts 
to the end of this table.