Check whether the Gigabit Ethernet switch generates an alarm mechanism easily

It is easy to check whether a Gigabit Ethernet switch generates an alarm mechanism. to check whether a Gigabit Ethernet switch generates an alarm mechanism, I have made many attempts. Can not easily deal with their own needs, so in the following article, alarmSampleType determines whether to compare with the threshold value by the absolute value of the sample or by the difference.

The values of alarmStartupAlarm and alarm-status in the alarm group in MIB jointly determine what alarms can be generated.

AlarmStartupAlarm is the alarm type set by the management site and remains unchanged during monitoring. If the value is 1, the alarm can be raised. If the value is 2, the alarm can be dropped. If the value is 0, both alarms are allowed. Alarm-status indicates the status of the alarm. The initial value is 0. Both Alarms can be generated.

Gigabit Ethernet switch: When an alarm is generated, set the alarm-status value to 2 to allow only a drop alarm; When a drop alarm is generated, set the alarm-status value to 1, and only the alarm can be raised. This is to avoid repeated alarms due to jitter.

AlarmSampleType determines whether to compare the value with the threshold value by the absolute sample value or the difference value.

If the absolute value of sampling is used, compare the sample value with the rising alarm threshold alarmRisingThreshold In the MIB when only the rising alarm is allowed. If the value is greater than the threshold, an increasing alarm is generated. When only the falling alarm is allowed, compare the sample value with the drop alarm threshold alarmFallingThreshold. If the value is smaller than the threshold, a drop alarm is generated. If both alarms are allowed, both methods must be compared.

If sampling difference is used, the difference is obtained from the sample-samlpe0. Then compare with the above method. After the comparison, the current alarmValue value is assigned to sample0 In the parameter table. When an alert is detected, the corresponding event definitions are found in the event group MIB Based on the event index in the alert table, and the records of the Gigabit Ethernet switch logs are determined to send SNMP trap messages.

Gigabit Ethernet switch conclusion

In a switched environment, to continuously monitor traffic, you need to embed the basic four groups of statistics, history, alarms, and event groups of RMON on each switching port. With the key four groups of RMON functions, you can achieve continuous real-time network monitoring, historical traffic statistics, and alarm and warning functions.

Because the traffic statistics can already be implemented by ASIC, the four basic functions of RMON can be embedded into a Gigabit Ethernet switch, which only occupies a small amount of resources in the Gigabit Ethernet switch. Other RMON function groups, such as packet filtering and capturing, require higher CPU memory resources. Put such a function group on a more powerful, but more cost-effective external mobile RMON monitor, you can get more cost-effective.

This article introduces the embedded RMON proxy of the Gigabit Ethernet switch to implement the four basic functions of RMON. Of course, when demand and system resources permit and underlying hardware support are available, it is also possible to embed all nine functions of RMON into a Gigabit Ethernet switch.

In addition, the RMON technology is constantly evolving. The emergence of RMONII and SMON technologies has greatly enhanced the network monitoring functions provided by RMON. Designers should choose to embed RMON functions into network devices based on the needs of different network applications.