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The options explained in this topic are available in the General tab of the Discovery Configurator.
Enabling/Disabling Auto-discovery
By default, the discovery process is automatically initialized when WebNMS Server is started.
To disable auto-discovery
In the General tab of the Discovery Configurator, deselect AutoDiscovery. By default, this option is enabled.
A warning message is displayed. Click Yes to disable auto-discovery.
Click Apply or from File menu, choose Save Changes.
Disabling this option will stop discovery process, i.e., auto-discovery will not happen when WebNMS Server is started. If you disable and then re-enable the AutoDiscovery option without shutting down or restarting the server, the discovery engine will just proceed with the rediscovery process according to the values set for the parameters, and there will not be any change in the already specified parameters.
Rediscovering already Discovered Devices
By default, the rediscovery process discovers only devices that were not discovered previously. It does not rediscover the already discovered devices.
To rediscover already discovered devices
In the General tab of the Discovery Configurator, click Rediscover Already Discovered. By default, this option is disabled (not selected).
Click Apply or from File menu, choose Save Changes.
When the discovery process reschedules itself, based on the rediscovery interval specified, enabling or disabling this field decides the functionality of the discovery process. By default, this option is disabled. If enabled, during rediscovery, all the devices (discovered and undiscovered) will be rediscovered.
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Note: The above parameter does not control the behavior for DHCP nodes. DHCP nodes will be rediscovered every time and the objects in the database are updated with the latest information. |
Preventing Local Network from Being Discovered
By default, the local network and all its nodes are discovered. You can prevent the discovery of local network using the Discover LocalNet option.
To prevent local network discovery
In the General tab of the Discovery Configurator, deselect Discover LocalNet. By default, this option is enabled.
Click Apply or from File menu, choose Save Changes.
By default, detailed discovery-related debug messages are logged in discoveryLogs.txt file located in the <WebNMS Home>/logs directory.
To disable/enable logging of debug messages
In the General tab of the Discovery Configurator, select/deselect Enable Log. By default, this option is enabled.
Click Apply or from File menu, choose Save Changes.
The interval between discovery of two devices in the network can be controlled using the Discovery Interval option. The value set for this parameter determines the performance (CPU utilization and network traffic) of the discovery process.
To set the discovery interval
In the General tab of the Discovery Configurator, enter the interval value (in seconds) in Discovery Interval. The value can be greater than or equal to zero and the default value is 1 second.
Click Apply or from File menu, choose Save Changes.
Initial discovery process is the first discovery process that is started as soon as the WebNMS server is started (cold start or warm start). The configurations set here determine the speed of the initial discovery process. It is not mandatory to set the values for all the parameters.
This configuration applies only to the initial discovery process. For subsequent discoveries, the configuration values provided in General tab are used. When no parameters are set in the Initial Parameters section, WebNMS, by default, takes up the values set for the parameters in General tab, which is applicable both to the initial discovery process and for the subsequent discoveries.
To set initial discovery parameters
In the General tab of the Discovery Configurator, click Initial Parameters. The Initial Parameters dialog box is displayed.
Enter the required values and click OK.
Click Apply or from File menu, choose Save Changes.
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Tip: Setting a value "0" to Discovery Interval option present in Initial Parameters dialog box is preferable, because these entries set in Initial Parameters are considered during the first start of the WebNMS server. During the successive rediscovery processes, the entries that are provided under the Discovery Interval (in General Configuration) and Native Ping options for the corresponding discovery parameters are taken into consideration. Hence, set "0" for Discovery Interval in Initial Parameters and give "1" or "2" for Discovery Interval in General Parameters. |
The options available in Initial Parameters are tabulated below:
| Parameter | Description |
|---|---|
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Discovery Interval |
Interval (in seconds) between the discovery of any two devices in the network.
Default value: 1 second |
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Rediscovery Interval |
Interval (in hours) between two complete discoveries of a network.
Default value: 24 hours
If a negative value is given, it is replaced by 24. |
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ICMP Ping Retries |
Number of ICMP ping retries (status polling). This is used while pinging to discover the network.
Default Value: 0 (i.e., retry is performed only once)
If you set the value as 1, then retry is done twice. Setting this value at minimum gives better performance. |
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SNMP Timeout |
Threshold value, in seconds, for all the SNMP requests.
This value is the maximum time that the requesting process waits for the first response, before attempting a retransmission.
It is useful when the discovery engine is discovering a remote network where the response time could be more.
Default value: 2 seconds
This value grows exponentially for each retries. This value is doubled for each retry. For example, if the timeout value is set to 5 seconds and retries set as 2, the first retransmission will happen after 5 seconds. The second after 15 seconds and so on. |
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SNMP Retries |
Number of SNMP retries for discovery, status polling, and data collection.
Default value: 0 (i.e., retry is performed only once)
If you set the value as 1, then retry is done twice. Setting this value at minimum gives better performance. |
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NativePing Timeout |
Threshold value for Native Ping.
Default value: 1 second |
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NativePing Retries |
Number of retries for Native Ping.
Default value: 1 second |
The scheduled interval (in hours) between two complete discoveries of the networks can be configured. When pinging all the IP addresses in a network is finished, it waits for the specified time before starting the rediscovery of the networks.
You can schedule the rediscovery process by specifying the rediscovery interval in hours. The rediscovery process can also be configured to run at a specific hour on a specified date of the month or specified day of the week.
You can set the Rediscovery Interval using one of the following options:
To set the rediscovery at Regular Interval
The time interval between two complete discovery of networks can be configured using the Regular Interval option. When regular time interval for rediscovery is configured (say 'x' hours), the WebNMS discovery engine, after discovering the IP Addresses in the network, waits for the specified 'x' number of hours before starting to rediscover the network again.
Click General tab in the Discovery Configurator.
Click Rediscovery. The Rediscovery Scheduler dialog box is displayed.
Click the Regular Interval option.
Specify the rediscovery interval in Hours, Minutes, and Seconds (as required). By default, the interval is set as 24 hours. You can set any value from 1 to 24 in the hours field. When you specify -1, rediscovery will be based on the entries configured in the User's Schedule UI option. When you give a negative value other than -1, the rediscovery interval will be taken as 24.
Click OK.
For example, if you have set the interval at 6 hours, after the initial discovery, WebNMS starts rediscovery after 6 hours.
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Note: If the Rediscovery Interval is set using Regular Interval option, then the values set for Specific Dates and Days of Week options will not take effect. |
To set rediscovery on specific dates
Click General tab in the Discovery Configurator.
Click Rediscovery. The Rediscovery Scheduler dialog box is displayed.
Click the Specific Dates option.
To choose a specific date on which rediscovery occurs, click the appropriate date option:
All Dates: Selects all the dates of a month and indicates rediscovery occurs every day.
Specific
Dates: Constitutes a range of days. For example, if you select
5 and 15, then the rediscovery will take place from the 5th to 15th of
every month.
When a particular month does not have the specified date, the
rediscovery will occur based on the number of days difference between
the current month and the next month. For example, if the specified date
is 31 and the current month is October. As per this configuration, the
rediscovery should occur after a range of 31 days. But the next month
November does not have 31. In this case, rediscovery will be scheduled
on 1st December (i.e., current month date 31 + specified date[31]). This
is because all these calculations are in terms of milliseconds. Similarly
if the date is specified as 31 and the current month is February (28 days),
then the rediscovery is scheduled on 3rd March.
Select one of the Hour options:
All Hours: Selects all the hours in a day.
Specific Hours: Selecting a specific hour in day.
Click OK after you select the option.
To set rediscovery on specific days
Click General tab in the Discovery Configurator.
Click Rediscovery. The Rediscovery Scheduler dialog box is displayed.
Click the Days of Week option.
To choose a specific day on which rediscovery occurs, click the appropriate day option:
All Days: Selects all the days of the week.
Specific Days: Selecting specific days of the week. For example, if you select Tue and Fri, the rediscovery occurs only on those days, every week.
Select one of the Hour options:
All Hours: Selects all the hours in a day.
Specific Hours: Selecting a specific hour in day.
Click OK after you select the option.
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Note:
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Combination of configurations that you can effect for rediscovery interval are listed in the table given below [based on seed.file configuration]:
| When do you want rediscovery
to take place? |
Rediscovery Interval |
Hour |
Dates |
Days |
|---|---|---|---|---|
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Default |
24 |
Any entry specified here will not take effect |
Any entry specified here will not take effect |
Any entry specified here will not take effect |
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Particular Hour(s) |
-1 |
Desired hour |
No value should be configured |
No value should be configured |
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Particular Day for every week |
-1 |
No value should be configured |
No value should be configured |
Desired days |
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Particular Date for every month |
-1 |
No value should be configured |
Desired dates |
No value should be configured |
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Particular Hour on a Particular Day |
-1 |
Desired hour |
No value should be configured |
Desired day |
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Particular Hour on a Particular Date |
-1 |
Desired hour |
Desired date |
No value should be configured |
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