Verify communication settings

After you configure your communication settings and wait until Auto-Discovery completes at least one cycle, you can verify your communication settings.

You can fine tune NNMi's SNMP/ICMP traffic in the following ways:

• Minimize timeouts and retries.

  When NNMi attempts to contact a node using ICMP / SNMP during an Auto-Discovery cycle, the Communication Configuration settings determine what information NNMi can gather. If the correct ICMP / SNMP settings are not provided or if NNMi discovers non-SNMP devices, NNMi resorts to timeouts and retries.

  Large timeout values or a high number of retries can degrade overall performance of discovery. If your network environment contains nodes that you know respond slowly to ICMP / SNMP requests, consider using the Regions or Specific Nodes settings to fine tune the number of timeouts and retries NNMi uses during each Auto-Discovery cycle.

• Limit the number of default SNMPv1/SNMPv2c Community Strings to ensure efficient Auto-Discovery performance.
• Limit the number of default SNMPv3 user-based security model (USM) settings to ensure efficient Auto-Discovery performance.

Verify that all nodes support SNMP

After you configure your communication settings and wait until Auto-Discovery completes at least one cycle, check for any nodes that do not respond to SNMP:

1. From the workspace navigation panel, select the  Inventory workspace.
2. Select the Nodes view.
3. Right-click the Device Profile column, and select Create Filter.
4. Select "contains", and type the following text into Enter a string: No SNMP.
5. NNMi displays a list of all nodes in your network environment that did not respond to SNMP during Auto-Discovery.
6. Verify that the resulting list is valid.

7. To troubleshoot unexpected results:

   • Verify a node's communication settings
   • Identify unexpected overrides of communication settings
   • Resolve authentication errors

Verify a node's communication settings

After you configure your communication settings and wait until Auto-Discovery completes at least one cycle, you can check to determine what settings NNMi is using to communicate with a node of interest.

NNMi provides a report about the communication configuration information for a selected node, including the SNMP and ICMP configuration information.

To display a report of a node's current communication settings:

The User Account must be assigned to the NNMi Administrators User Group to use this action.

1. Do one of the following:

   Navigate to a table view and select a node:

   1. From the workspace navigation panel, select the workspace of interest. For example,  Inventory.
   2. Select the view that contains the node with communication settings you want to check. For example, Nodes.
   3. Select the row representing the node with communication settings you want to check.

   Navigate to a map view and select a node:

   1. From the workspace navigation panel, select the workspace of interest; for example,  Topology Maps.
   2. Click the view that contains the node with communication settings you want to check; for example Initial Discovery Progress or Network Overview map.
   3. From the map view, click the node with communication settings you want to check.

   Navigate to a Node form:

   • From a table view, double-click the row representing the node of interest.
   • From a map view, click the node of interest on the map and click the  Open icon.
2. Select Actions > Polling > Communication Settings.

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

Sometimes a device is temporarily not responding properly to SNMP during NNMi's initial discovery, so NNMi makes the wrong decision about which version of SNMP to use. Or perhaps you deployed upgrades to the SNMP agents in your network environment.

To update NNMi's choice of SNMP version used for a Node or Nodes:

The User Account must be assigned to the NNMi Administrators User Group to use this action.

1. From the workspace navigation panel, select  Inventory.
2. Select the Nodes (All Attributes) view.
3. Click the Protocol Version column heading to sort the view according to SNMP version currently being used by NNMi for communications with each SNMP agent in your network environment.
4. Select all rows that you want NNMi to check for SNMP upgrades or changes.

5. select Actions > Polling > Configuration Poll.

   NNMi reconfigures the SNMP Communication settings by verifying the highest SNMP version available to the SNMP Agent assigned to the node (according to your Communication Configuration settings).

6. Click the Protocol Version column heading to resort the view according to SNMP version.

7. Verify that NNMi made the expected changes.

To verify your Communication Configuration settings:

The User Account must be assigned to the NNMi Administrators User Group to use this action.

1. Do one of the following:

   Navigate to a table view and select a node:

   1. From the workspace navigation panel, select the workspace of interest. For example,   Inventory.
   2. Select the view that contains the node with communication settings you want to check. For example, Nodes.
   3. Select the row representing the node with communication settings you want to check.

   Navigate to a map view and select a node:

   1. From the workspace navigation panel, select the workspace of interest; for example,  Topology Maps.
   2. Click the view that contains the node with communication settings you want to check; for example Initial Discovery Progress or Network Overview map.
   3. From the map view, click the node with communication settings you want to check.

   Navigate to a Node form:

   • From a table view, select the row representing the node of interest.
   • From a map view, click the node of interest on the map and click the  Open icon.

2. Select Actions > Configuration Details > Communication Settings.

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

   NNMi displays a report showing ICMP and SNMP communication configuration settings for this node's SNMP Agent.

   (NNMi Advanced) If the Global Network Management feature is enabled and you are signed into a Global Manager:

   • Node managed by the Global Manager = Actions → Configuration Details → Communication Settings opens a report, provided by the Global Manager (NNMi management server).

   • Node managed by a Regional Manager = Actions → Configuration Details → Communication Settings accesses that Regional Manager (NNMi management server) and requests the report.

     You must sign into that Regional Manager unless your network environment enables Single Sign-On (SSO) to that Regional Manager through the Global Manager.

Resolve authentication errors

To create a list of authentication errors:

1. From the workspace navigation panel, select the  Incident Browsing workspace.
2. Select an Incident view.
3. Right-click the Category column, and select Create Filter.
4. Select "equals", and select   Security.
5. NNMi displays a list of all incidents related to authentication errors; for example an SNMP authentication failure.

If NNMi generates incidents related to authentication failure during discovery, there are several configuration settings that influence authentication errors:

• Communication Configuration.

  Each Node’s Management Address is the address NNMi uses to communicate with the Node’s SNMP agent. The NNMi administrator can control NNMi behavior:

  • Specify the Management Address for a node (in the Communications Configuration, Specific Nodes settings).
  • Otherwise, let NNMi choose an address from all IP addresses associated with each node. This NNMi behavior can be fine-tuned by the NNMi administrator in the Discovery configuration settings.

  Consider configuring smaller Regions with more focused lists of possible access credentials. Or configure Specific Nodes to avoid requiring NNMi to try multiple possible settings.

• Discovery Configuration.

  The following Discovery Configuration fields influence NNMi’s use of SNMP:

  • Discover Any SNMP Device field.

    If  disabled, NNMi discovers only Routers and Switches that respond to SNMP.

    If  enabled, NNMi discovers all devices that respond to SNMP.

  • Discover Non-SNMP Devices field.

    If disabled, when there is no SNMP response from the device, NNMi does not discover information about the device or add a record of that device to the NNMi database.

    If enabled, NNMi discovers devices that do not respond to SNMP and assigns the Device Profile named No SNMP as the basis of the database record.

  NNMi's access to SNMP agents is also influenced by the set of rules for choosing management addresses and settings to exclude certain addresses.

• Device Profiles.

  The Device Profiles' Force Device attribute setting influences NNMi’s use of SNMP.

• Monitoring Configuration.

  NNMi discovers and monitors devices in an ongoing basis. For example, when previously discovered SNMP agents quit responding (such as when you reconfigure the device’s SNMP agent), NNMi detects the alternatives.

  To control management address rediscovery after the first NNMi discovery cycle, use Communication Configuration's Enable SNMP Address Rediscovery field:

  • If  disabled, when the current management address (SNMP agent) becomes unreachable, NNMi does not check for other potential management addresses.
  • If  enabled, NNMi retries any configured values in search of one that works.

Related topics

• Discover Your Network
• NNMi Security and Multi-Tenancy