Administer > Discover your network > Configure Discovery > Establish Global Defaults for Spiral Discovery

Establish global defaults for spiral discovery

The Global Defaults determine the following:

  • Enable/Disable ATM / Frame Relay Interfaces for Performance Monitoring.
  • Enable/Disable Ping Sweep for Auto-Discovery of IPv4 addresses.
  • Configure the strategy NNMi uses to determine Node Names.
  • Specify zero or one Node Group from which Spiral Discovery will ignore the Forwarding Database (FDB) data when calculating Layer 2 Connections (the FDB data is still included in other calculations).

Configure discovery of ATM/Frame Relay interfaces

Requires NNM iSPI Performance for Metrics. To populate performance data in the dashboard views or enhance NNM iSPI Performance for Metrics reports by sharing NNMi configuration settings, install the optional Network Performance Server (NPS).

If your network environment includes devices that are using Asynchronous Transfer Mode (ATM) or Frame Relay protocols, NNM iSPI Performance for Metrics can provide useful information about network activity that is using those protocols.

To enable/disable Discovery of ATM/Frame Relay Interfaces:

  1. Navigate to the Discovery Configuration form.

    1. From the workspace navigation panel, select the  Configuration workspace.
    2. Expand Discovery.
    3. Select Discovery Configuration.
  2. Locate the Global Control settings.

  3. Specify the ATM/Frame Relay Discovery setting.

    Enable Discovery of ATM/Frame Relay Interfaces for Performance Monitoring:

    If  enabled, this attribute extends the range of data that NNMi  gathers for ATM and Frame Relay interfaces.

    If  disabled NNMi does not discover and gather the extended ATM and Frame Relay data that NNM iSPI Performance for Metrics uses for reporting purposes.

  4. Click  Save and Close to apply your changes.

Configure ping sweep

Default Tenant only: You have two choices for Auto-Discovery starting points. Use either or both to best advantage in your network environment:

  • Discovery Seeds: You designate specific hostnames (not case-sensitive) or IP addresses where Auto-Discovery starts gathering neighbor information.

  • Ping Sweep: NNMi issues ICMP pings to certain addresses to find new nodes.

    IPv4 addresses only: In Wide Area Networks (WANs) such as ATM, Frame Relay, and Point-to-Point (where ARP cache is not available), the optional Ping Sweep for Auto-Discovery in Default Tenant feature locates nodes for Auto-Discovery to use when gathering neighbor information and evaluating connections between nodes.

    Ping Sweep works only with IPv4 addresses and only in 16-bit subnets. All nodes discovered using Auto-Discovery are assigned to the Default Tenant.

Ping Sweep uses the current default ICMP interval and timeout settings from the Communications Configuration settings.

To configure the global Auto-Discovery setting for Ping Sweep:

  1. Navigate to the Discovery Configuration form.

    1. From the workspace navigation panel, select the  Configuration workspace.
    2. Expand Discovery.
    3. Select Discovery Configuration.
  2. Navigate to the Global Control settings.

  3. Designate the global setting for Ping Sweep. Your choice determines how Auto-Discovery uses ICMP ping commands for the discovery process in your network environment:

    • Each Rule (as configured)— The instructions for Ping Sweep within each Auto-Discovery Rule configuration are followed exactly.

    • All Rules— Ping Sweep is applied for all of your current Auto-Discovery Rules. This overrides the Ping Sweep settings within each rule. Spiral Discovery issues the initial round of Ping Sweep commands when you click Save and Close.
    • None— Ping Sweep is not used for any of your current Auto-Discovery Rules. This overrides the Ping Sweep settings within each rule. This is useful to temporarily suspend issuing any ping commands within your network.

    If things do not work as expected, check whether ICMP is enabled.

  4. Designate the Sweep Interval (days/hours) that controls how often Auto-Discovery reissues ICMP Ping for each address. The minimum Sweep Interval setting is 1 hour. Maximum 99 days.
  5. Click  Save and Close. Spiral Discovery issues the initial round of Ping Sweep commands when you click Save and Close.

Configure the node name strategy

NNMi administrators control how the Name attribute on the Node form is populated. To resolve issues about choosing the Name value, NNMi follows a sequence of rules. If NNMi is unable to determine a Name based on your three choices, the node name is determined using the NNMi factory defaults for these three choices (see list in step 3).

The node Name shows up beneath the node symbol on the maps and in the Name column on table views.

To control how node names are determined for your network devices:

  1. Navigate to the Discovery Configuration form.

    1. From the workspace navigation panel, select the  Configuration workspace.
    2. Expand Discovery.
    3. Select Discovery Configuration.
  2. Locate the Node Name Resolution attributes on the left side of the form (see table).

  3. Specify the three-level hierarchy for node naming decisions.

    Short name and full name are related. The short name is everything before the first period in the full name. For example, full name cisco5500.abc.example.com and the short name cisco5500.

    NNMi administrators can use NNMi property file settings to change the way NNMi determines Hostname values:

    • nms-topology.properties file settings:
      If DNS is the source of the Node's Hostname, there are three choices. By default NNMi uses the exact Hostname from your network configuration. It is possible to change NNMi behavior to convert Hostnames to all uppercase or all lowercase.
    • nms-disco.properties file settings:
      The Hostname is either requested from the Node's lowest loopback interface IP address that resolves to a Hostname or requested from the Node's designated Management Address (SNMP agent address). With either choice, when no IP address resolves to a Hostname, the IP address itself becomes the Hostname.

    Select among the following choices. Use each choice only one time:

    • Short DNS Name – (first by default) Use the group of characters before the first period in the node's DNS name.
    • Full DNS Name – Use the fully-qualified DNS name.
    • Short sysName – (second by default) Use the group of characters before the first period in the current MIB-II sysName value established by the administrator for each SNMP enabled device.
    • Full sysName – Use the full MIB-II sysName value established by the administrator for each SNMP enabled device.

    • IP Address – (third by default) Use the IP address. If the node responds to SNMP, the SNMP Management Address is used. For non-SNMP nodes, name is set to either a discovery seed address associated with this node or a neighbor address gathered by Auto-Discovery along the path to this node.

      NNMi administrators choose how NNMi uses address protocols:

      • The Excluded IP Addresses filter, Spiral Discovery skips addresses or ranges of addresses configured in this file.
      • The IP Version Preference setting, NNMi Advanced uses IPv4 addresses, IPv6 addresses, or dual-stack (both) addresses according to configuration choices.

  4. Click  Save and Close. Spiral Discovery implements your changes during the next regularly scheduled discovery interval. To apply the changes immediately, use Actions > Polling > Configuration Poll.

    You can also right-click any object in a table or map view to access the items available within the Actions menu.
Node Name Resolution Settings
Attribute Description
First Choice Click the drop-down list and choose the predefined node name strategy you want discovery to use first.
Second Choice Click the drop-down list and choose the predefined node name strategy you want discovery to use if the first choice fails.
Third Choice Click the drop-down list and choose the predefined node name strategy you want discovery to use if the second choice fails.

Discovery node name choices

Control how the Name attribute on node forms is populated during discovery. This Name value is used to identify the object in NNMi maps and table views. You specify a hierarchy for discovery to use. You configure three levels in the hierarchy. S

You can designate any of the following for each level of the node Name decision hierarchy:

  • DNS Names. Discovery uses the results of hostname resolution.

    NNMi follows a set of rules to dynamically generate the value stored in the NNMi database for each Node's Hostname.

    • If the Node supports SNMP, NNMi requests the Hostname using the IP Address of the associated SNMP agent (the Management Address attribute value on the Node form).

      When the NNMi administrator chooses Enable SNMP Address Rediscovery  in the Communication Configuration:

      • If the SNMP Agent does not respond, NNMi checks for another Management Address to request the Hostname, and the Hostname could change.
      • If the SNMP Agent associated with the node changes, the Management Address and Hostname could change.

      When the NNMi administrator disables Enable SNMP Address Rediscovery  in the Communication Configuration, when the current management address (SNMP agent) becomes unreachable, NNMi does not check for other potential management addresses.

    • If the Node does not support SNMP, no Management Address is available. NNMi requests a Hostname starting with the lowest IP Address associated with the node (a Discovery Seed value or an IP address value gathered from a neighboring device). NNMi uses the first Hostname provided. The Hostname might change during a future discovery cycle.

    NNMi administrators can use NNMi property file settings to change the way NNMi determines Hostname values:

    • nms-topology.properties file settings:
      If DNS is the source of the Node's Hostname, there are three choices. By default NNMi uses the exact Hostname from your network configuration. It is possible to change NNMi behavior to convert Hostnames to all uppercase or all lowercase.
    • nms-disco.properties file settings:
      The Hostname is either requested from the Node's lowest loopback interface IP address that resolves to a Hostname or requested from the Node's designated Management Address (SNMP agent address). With either choice, when no IP address resolves to a Hostname, the IP address itself becomes the Hostname.

  • MIB-II sysName Values. Device administrators set the sysName. Discovery avoids populating the NNMi database with multiple devices having the same manufacturer's default sysName. If a sysName matches or starts with the manufacturer's default factory setting (case-sensitive), discovery ignores sysName as a choice for the Name attribute of the node. NNMi ships with a Device Profile for each device type (vendor/make/model). The Device Profile includes a record of the manufacturer's default sysName.

    Caution You can override this choice using the Device Profile's Advanced settings, Never Use sysName attribute.

  • IP addresses. The addresses are gathered from discovery seed addresses that you provided, ping sweep configurations, or neighbor addresses gathered using Auto-DiscoveryRules. Discovery avoids potential confusion when a device has multiple IP addresses by following these rules:

    • If the device supports SNMP, the address of the responding SNMP agent is recorded (the Management Address) and the other addresses are associated with the node.

    • If the device does not support SNMP, NNMi queries DNS to determine the hostname. If this hostname matches another non-SNMP node, NNMi merges the information to create only one node with multiple associated addresses.

Node name decision tree

NNMi gathers multiple attributes that are used to implement the NNMi Administrator's choice of Node Name strategy.

NNMi chooses the Node Name based on the Management Address, System Name, and Hostname collected during discovery. The following diagram shows how NNMi determines values for these attributes.

If you change a node's Hostname, there is a delay before NNMi data reflects the name change, because NNMi caches DNS names to enhance performance.

Configure Layer 2 connection source

(NNMi Advanced - Global Network Management feature) Both of the settings described below depend on your Node Group definitions.

Optional: To configure NNMi for calculating FDB and unnumbered interface influence on Layer-2 Connections:

  1. Navigate to the Discovery Configuration form.

    1. From the workspace navigation panel, select the  Configuration workspace.
    2. Expand Discovery.
    3. Select Discovery Configuration.
  2. On the left side of the form, locate Layer 2 Connection Source.

  3. (Optional) Configure the Node Group to disable FDB setting.

    Forwarding Database (FDB) information can cause NNMi to establish wrong Layer 2 Connections in the following cases:

    • When the FDB is configured as cache and contains obsolete data.
    • In network environments with hardware from a variety of vendors, when each vendor generates different and sometimes conflicting FDB data.

    Optional: NNMi administrators can configure Spiral Discovery to ignore the FDB data from one Node Group when calculating Layer 2 Connections (the FDB data is still included in other calculations).

    To specify which Node Group's FDB information will be ignored, do one of the following:

    • Click the drop-down list and choose a previously defined Node Group.
    • Select the  Lookup icon and select  New to create a new Node Group.

    (NNMi Advanced - Global Network Management feature) NNMi must read the Forwarding Database (FDB) tables from Ethernet switches within the network before accurate communication paths between these network devices can be calculated. Because FDB data is involved, NNMi can produce different results on a Regional Manager as opposed to the Global Manager.

  4. (Optional) Configure the Enable Unnumbered Interface Connectivity setting.

    Unnumbered interface connectivity involves querying routing tables, which can generate a lot of network traffic when the routing tables are large. If your network environment requires monitoring of unnumbered interfaces, configure the following:

    • Enable this setting:
      Enable Unnumbered Interface Connectivity

      (NNMi Advanced - Global Network Management feature) This attribute must be enabled on each Regional Manager and the Global Manager.

    • Use the Unnumbered Interface Node Groups tab or nnmunnumberedcfg.ovpl command-line tool to designate the following:

      • Which Node Groups will have Layer 2 Connectivity
      • (Optional) Which specific subnets within each participating Node Group will be monitored for Layer 2 Connectivity. These settings serve as a filter to further limit NNMi's discovery and monitoring of unnumbered interfaces.

  5. Click  Save and Close. Spiral Discovery implements your changes during the next regularly scheduled discovery interval. To apply the changes immediately, use Actions > Polling > Configuration Poll.

    You can also right-click any object in a table or map view to access the items available within the Actions menu.

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