5.2.2 Planning the objects to be monitored by state polling
By default, the NNMi State Poller uses SNMP polls to monitor the following:
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Interfaces that are connected to another known interface on an NNMi-discovered device
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Router interfaces that host IP addresses
- Reference note
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In most cases, polling only connected interfaces provides sufficiently accurate root-cause analysis. Extending the set of monitored interfaces can impact polling performance.
- Extending monitoring
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You can extend the monitoring to include the following:
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Unconnected interfaces. By default, the only unconnected interfaces that NNMi monitors are those that have IP addresses and are included in the Routers node group.
- Reference note
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NNMi defines an unconnected interface as an interface that is not connected to another device discovered by NNMi, as shown below.
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- Organization of this subsection
(1) Interfaces to unmonitored nodes
Sometimes, you need to know the status of an interface that connects to a device you do not manage directly. For example, you want to know whether the connection to an application or Internet server is up, but you might not be responsible for maintaining that server. If you do not include the server in the discovery rules, NNMi sees the interface that faces the server as unconnected.
There are two ways to monitor the status of an important interface that connects to an unmonitored node:
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Discovering the unmonitored node
When you add an unmonitored node to the NNMi topology, NNMi sees the interfaces connecting the node to the rest of the topology as CONNECTED. Then NNMi can poll these interfaces according to the monitoring configuration. NNMi discovers the node as Managed. For nodes that you do not want NNMi to monitor, you will need to set the mode to Not Managed.
- Reference note
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Each discovered node counts toward the license limit, regardless of whether NNMi is actively managing that node.
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Polling the unconnected interface
You can create a node group containing the network devices that provide connectivity for undiscovered nodes. Then enable polling of unconnected interfaces for the node group.
NNMi polls all interfaces on the devices in the node group, which can add a lot of traffic for a device with many interfaces.
(2) Stopping monitoring
The NNMi management modes are used to set devices or interfaces to Not Managed or Out of Service. The Not Managed mode is considered to be a permanent situation; you will never care about knowing the status of such objects. Out of Service is for a temporary situation where one or more objects will be offline and a down incident would be superfluous.
Consider the management mode as an overlay across all group settings. Regardless of an object's group, polling interval, or type, the State Poller does not communicate with the object when its status is set to Not Managed or Out of Service.
- Tip
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Some devices, interfaces, or both that you choose to be discovered and placed in the database do not need to be polled. You will permanently set such objects to Not Managed. You might want to create one or more node groups to enable you to set management modes more easily.