SNMP Graph Item Properties
Use the Graph Item Properties dialog box to add
an SNMP item to the graph or change an item's properties.
- In the box, enter the hostname or IP address
of the device for which you want to graph SNMP objects, or select
one from the list box.
- If necessary, change the string in the
default string is
The default (public) will work for most SNMP devices unless the
administrator has specifically removed public and replaced it with a string of their own.
If you know a device is manageable via SNMP and public doesn't work, you will have to talk to the
owner of that device to get a community name that will
- Use the and boxes along with the MIB tree to
select the SNMP object that you want to graph.
If you know the object identifier for the
SNMP object, you can enter it in the box.
To browse the available SNMP objects, click
the browse button and use the MIB tree. Select an object in the MIB
tree and click to enter its
object identifier in the
Use the box to enter the instance of the
selected SNMP object.
- Set any of the following options to
determine how to graph the values for the SNMP object:
- . When selected (or turned on), graphs the reported
values of an SNMP object rather than graphing the change between
the last reported value and the current value (which is the default
method). When graphing a counter, such as ifOutOctets, the reported
values will continuously increase, so if you select Absolute
values, the graph will continue to "stair-step" up the scale.
Counters are best graphed using the default method, which uses the
change in value. Absolute values are appropriate for SNMP objects
that have integer values, such as the number of FTP users on an FTP
- . When selected, the graph scale
for the SNMP object is determined by the graphing utility. This is
a relative scale that is calculated to make the graph fit into the
vertical scale. If you turn off this option, the option becomes active and you can
enter a value to scale the graph.
When is cleared (not
checked), you can enter a fixed value in this text box to determine
the scale of the graph. You may want to try different values in
this box until you find a scale that is useful.
- . When selected, multiplies the value reported for the
SNMP object by 8 to approximate the count in bits, and then graphs
the result. This option can be used with SNMP objects that are
counters, for example if you want to know the baud rate while
monitoring a T1 router port, you want (ifOutOctets * 8) to give you
a value close to the real baud rate.
- . When selected, it calculates the average change
per second in the values reported for the SNMP object, and then
graphs the result. To calculate this average, it takes the
difference between the latest reported value and the previously
reported value, then divides by the number of seconds between
reported values. This is useful when the graph is different than one second. You
cannot use this option with the option.
- . When selected, it clears the values for the
selected SNMP object when you exit the dialog box. You can clear
the values for all SNMP objects on the graph from the
menu by selecting
- . Sets the width of the line that represents the
selected SNMP object on the graph. Select a width from the list
Sets the color of the line that represents the selected SNMP object
on the graph. Select a color from the list box.
- Click to add the SNMP object to the graph.