Monitoring Your Network - Getting Started with NerveCenter Client - Setting Up Alarm-Instance Filters - Filtering Alarms by IP Range -
Setting Up Alarm-Instance Filters      Rules for Associating Filters with Alarms

Filtering Alarms by IP Range

When you filter alarms by IP range, you are specifying that you only want to display alarm instances in the NerveCenter Client from particular nodes identified by their IP addresses.

See IP Subnet Filter Exclusion Rules, for more information about filtering alarms by IP ranges.

Although you can create a filter simply based on an IP range, a single filter can contain any combination of:

For information on how to build an alarm-instance filter based on severities and property groups, see the respective section listed below:

 
  To create an alarm filter based on an IP range:

  1. Choose Configuration from the Client menu.

    The Client Configuration dialog is displayed.

    clientConfig212

  2. Select the Alarm Filter Modification tab.

    The Alarm Filter Modification page is displayed.

    alarmFilterModification14

  3. Select the New button.

    The Alarm Filter Definition dialog is displayed.

    alarmFilterDefinition15

    This is the dialog you use to define your filter.

  4. If you want to filter alarm instances based on the IP addresses of the alarm instances' nodes, perform the steps below for each subnet you want to be part of the filter. That is, you want to see information about instances whose nodes have IP addresses on these subnets.
    1. Enter an IP address in the Subnet text field.

      The IP address must consist of four octets separated by periods.

    2. Enter a subnet mask in the Mask text field.

      The subnet mask must consist of four octets separated by periods. Taken together with the subnet address, this mask defines the subnet whose nodes you're monitoring.

    3. In the Exclusion text field, enter the last octet of the IP address of any node on the subnet that you're not monitoring.

      You can enter multiple exclusions separated by commas. You can also enter a range of excluded nodes using a hyphen. For example, if you enter 24, 76-78 in the Exclusion field, the nodes whose addresses end in 24, 76, 77, and 78 will be excluded by the filter.

    4. Select the Add button.
    5. Repeat step a to step d to add other subnets to the alarm filter.
  5. Enter a name for your filter in the Filter Name field.
  6. Select the OK button.

    The Alarm Filter Definition dialog is closed and you return to the Client Configuration dialog box.

You've now defined an alarm filter based on an IP range. Before the client will use the filter, however, you must associate the filter with a server. For instructions on how to create this association, see the section Associating a Filter with a Server.

IP Subnet Filter Exclusion Rules

When you filter by subnet, you specify which subsets of nodes are managed by NerveCenter. Filtering does not apply to nodes that have been imported from a file or from another NerveCenter. For an example, see IP Subnet Filter Examples.

You can exclude specific nodes that belong to the filter by entering an exclusion. To exclude one or more nodes, you must specify the full subnet and mask, and then enter the individual nodes you want excluded. Enter the part of the IP address that is not affected by the subnet's mask.

NerveCenter filters Class B and C networks.

Class C Networks

In a Class C network, the first three octets of the address specify the network and the last octet specifies the host. For example, in network 194.123.45.0, the 194.123.45 value pertains to the network. The remaining octet is used to identify nodes (up to 254) on the network, and you can exclude nodes by specifying ID values in this octet.

Class B Networks

For a Class B network, only the first two octets of the address specify the network. For example, in network 132.45.0.0, the 132.45 value pertains to the network. The remaining two octets are used to identify nodes, and you can exclude nodes by specifying ID values in these two octets.

Example

In the following example, the node whose IP address is 134.204.179.40 is excluded from the filter (the node is filtered out and, therefore, is not managed by NerveCenter).


   134.204.179.0
   255.255.255.0
   40

Rules for Exclusions

IP Subnet Filter Examples

The following examples can help you understand how to filter nodes for Class B and C networks.

Class C Network

The following subnet filters are for two sample nodes:

The filter values in Class C Network Exampleshave the following effects on the sample nodes:

Class C Network Examples

Subnet Mask Exclusion Results of Filter

134.204.179.0

255.255.255.0

This filter does not contain any exclusions.

Node #1 is not on this subnet and is not included in the filter or managed by NerveCenter.

Node #2 is included in the filter because it's on the subnet.


134.204.179.0

255.255.255.0

25,40

Node #1 is not on this subnet and is not included in the filter.

Node #2 is listed as an exclusion and is not included in the filter.


197.204.179.0

255.255.255.0

7-20

Node #1 is included.

Node #2 is not included because it's listed in the exclusion range.


197.204.179.0

255.255.255.0

7-20

134.204.179.0

255.255.255.0

40

Node #1 is included in the first subnet.

Node #2 is not included because it's listed as an exclusion on both subnets.


197.204.179.0

255.255.255.0

25,40

Node #1 is not included because it's listed as an exclusion.

Node #2 is included.


Class B Filters

The following subnet filters are for two sample nodes:

The mask you use for this filter is 255.255.0.0.

Class B Filter Examples (Set One)

Subnet Mask Exclusion Results of Filter

132.45.0.0

255.255.0.0

Both nodes are included in the filter and managed by NerveCenter.


132.45.0.0

255.255.0.0

174.10

Node #1 is included in the filter.

Node #2 is excluded from the filter. The filter includes all nodes except 132.45.174.10.


132.45.0.0

255.255.0.0

160.10-174.5

Node #1 is listed in the exclusion range and is excluded from the filter.

Note #2 is included in the filter.


132.45.0.0

255.255.0.0

10

Both nodes are excluded from the filter and, therefore, neither node is managed by NerveCenter. The filter includes all nodes except 132.45.xxx.10, where xxx can be any value greater than 1 and less than 255.


If you use a subnet mask of 255.255.240.0, you would get different results.

You must first apply the filter before determining the node's ID. The filter values in the table below have the following effects:

Class B Filter Examples (Set Two)

Subnet Mask Exclusion Results of Filter

132.45.160.0

255.255.240.0

174.10

The node is not included in the filter. The filter includes all nodes except 132.45.174.10.


132.45.160.0

255.255.240.0

10

Neither node is included in the filter. The filter includes all nodes except those ending in .10. The third octet of an excluded node can be 174 or any value between 160 and 174.


Filtering Alarms by Severity

When you filter alarms by severity, you are specifying that you only want to display alarm instances in the NerveCenter Client from particular nodes identified by the severity of the alarm instance's state.

Although you can create a filter simply based on severity, a single filter can contain any combination of:

For information on how to build an alarm-instance filter based on IP range and property groups, see the respective section listed below:

 
  To create an alarm filter based on severity:

  1. Choose Configuration from the Client menu.

    The Client Configuration dialog is displayed.

    clientConfig216

  2. Select the Alarm Filter Modification tab.

    The Alarm Filter Modification page is displayed.

    alarmFilterModification17

  3. Select the New button.

    The Alarm Filter Definition dialog is displayed.

    alarmFilterDefinition18

    This is the dialog you use to define your filter.

  4. Select the Severity tab.

    The Severity tab is displayed.

    alarmFilterDefinitionSeverity19

  5. In the Available Severities list, for each severity you want to use in your filter, select the severity and then select the >> button. That is, you want to see information about alarm instances whose states have these severities.

    The severities in this list box are the union of the severities defined by all of the servers to which you're connected. Optionally, you can also add a user-defined severity to the list of severities to filter by entering a severity in the And User-specified Severity text box, and then selecting the >> button.

    The name of the severity is moved to the Selected Severities list. Information about alarm instances with this severity will be displayed in the alarm summary views.

    To remove a severity from the Selected Severities list, select the severity and then select the << button.

  6. Enter a name for your filter in the Filter Name field.
  7. Select the OK button.

    The Alarm Filter Definition dialog is closed and you return to the Client Configuration dialog box.

You've now defined an alarm filter based on severity. Before the client will use the filter, however, you must associate the filter with a server. For instructions on how to create this association, see the section Associating a Filter with a Server.

Filtering Alarms by Property Groups

When you filter alarms by property groups, you are specifying that you only want to display alarm instances in the NerveCenter Client from particular nodes belonging to one or more property groups.

Although you can create a filter simply based on membership within a property group, a single filter can contain any combination of:

For information on how to build an alarm-instance filter based on an IP range and severities, see the respective section listed below:

 
  To create an alarm filter based on property groups:

  1. Choose Configuration from the Client menu.

    The Client Configuration dialog is displayed.

    clientConfig237

  2. Select the Alarm Filter Modification tab.

    The Alarm Filter Modification tab is displayed.

    alarmFilterModification39

  3. Select the New button.

    The Alarm Filter Definition dialog is displayed.

    alarmFilterDefinition41

    This is the dialog you use to define your filter.

  4. Select the Property Group tab.

    The Property Group tab is displayed.

    alarmFilterDefinitionPropertyGroup44

  5. In the Available Property Groups list, for each property group of each alarm instance's node, perform the steps below for each property group you want to be part of the filter. That is, you want to see information about instances whose nodes belong to these property groups.

    The property groups in this list box are the union of the property groups defined by all of the servers to which you're connected.

    The name of the property group is moved to the Selected Property Groups list. Information about alarm instances with this property will be displayed in the alarm summary views. Optionally, you can also add a user-defined property group to the list of properties to filter by entering a property group in the And User-specified Property Group text box, and then selecting the >> button.

    To remove a property group from the Selected Properties list, select the property group and then select the << button.

  6. Enter a name for your filter in the Filter Name field.
  7. Select the OK button.

    The Alarm Filter Definition dialog is closed and you return to the Client Configuration dialog box.

You've now defined an alarm filter based on property groups. Before the client will use the filter, however, you must associate the filter with a server. For instructions on how to create this association, see the section Associating a Filter with a Server.

Associating a Filter with a Server

When you define an alarm filter, that filter is not used to filter alarm instances from all connected servers. It is only used to filter alarm instances from a server with which you have explicitly associated it.

 
  To associate an alarm filter with a NerveCenter server:

  1. Choose Configuration from the Client menu.

    The Client Configuration dialog is displayed.

    clientConfig213

  2. Select a server from the list of servers at the bottom of the dialog.

    The name of the server appears in the Server Name text field in the Connection Information group box. This is the server with which you will associate your alarm filter.

  3. Select the Alarm Filter Selection tab.

    The Alarm Filter Selection page is displayed.

    alarmFilterSelection20

  4. Select a filter from the Available Filters list.

    This is the filter you want to associate with the server you selected in step 2.

  5. Select the >> button to move the filter from the Available Filters list to the Selected Filters list.

    To remove a filter from the Selected Filters list, select the filter and then select the << button.

  6. Select the OK button at the bottom of the dialog.


Setting Up Alarm-Instance Filters Rules for Associating Filters with Alarms
29 July 2003