HP OpenView System Administration Handbook [Electronic resources] : Network Node Manager, Customer Views, Service Information Portal, HP OpenView Operations نسخه متنی

5.3 NETMON POLLING STATISTICS

Periodically you may want to check netmon's status. If you do this during network discovery you will find that netmon is very busy. You might also check when you suspect you have a network bottleneck or a network routing device is down. NNM provides a graphical representation of netmon's polling status, which can be accessed by selecting

PerformanceNetwork Polling Statistics from the menu bar. The Network Polling Statistics graph includes the following information:

• Seconds Until Next Status Poll

• Status Poll List Length

• Status Polls in Next Minute

• Seconds Until Next SNMP Poll

• SNMP Poll List Length

• SNMP Polls in Next Minute

The first variable, Seconds Until Next Status Poll, defines the number of seconds before NNM sends out an ICMP packet to determine the device status. By default, this type of poll is performed once every five minutes per device. This variable should always have a positive value. A negative value indicates that netmon is getting behind in its polling cycle. If a device does not respond to the status poll, netmon has a timeout (.8 by default, 800 milliseconds) and retry count (2 by default) that can cause the netmon polling cycle to get behind if a lot of devices are non-responsive. This could happen for the following reasons:

1. A portion of the network is unreachable due to a routing device outage

2. Faulty network equipment causes heavy packet loss

3. Initial network discovery

4. Too many devices being managed by NNM^{Chapter 7}, "Advanced Customization."

   The additional MIB variables displayed on the Network Polling Statistics graph include the number of devices in the list to be polled and the number of polls in the next minute. You will notice that these values increase during network discovery.