# Devices

NetObserv SNMP Trap makes it simple to manage the devices counting towards your license limit. NetObserv SNMP Trap uses the devices defined in the device store file to determine the number of devices that are being monitored. Whenever a new device sends a trap packet to the collector, an entry is automatically added to the device file and if the licensed count hasn't been reached the device is set to active. Otherwise uses are free to update the file manually to specify which devices to listen for. As an added feature, NetObserv SNMP Trap will automatically deactivate a device which has not been heard from in a specified number of days.

The location of the device definition files is specified by `EF_INPUT_TRAP_LISTENER_DEVICE_STORE_PATH` in the collectors configuration options. The default location is `/var/lib/elastiflow/trapcoll/devices.yml`.

### Listener Device File Example

**Full configuration:**

```yaml
127.0.0.1:
  ip: 127.0.0.1
  active: true
  last_received: 2024-09-28T23:10:47.665385-05:00
127.0.0.2:
  ip: 127.0.0.2
  active: true
  last_received: 2024-09-29T00:11:57.963101-05:00
127.0.0.3:
  ip: 127.0.0.3
  active: true
  last_received: 2024-09-29T00:11:04.876109-05:00
```

### Configuration Attributes

#### Device Key

The device key is the IP address of the device that is sending Trap requests to the collector.

EXAMPLE: `192.0.2.2`

#### ip

The IP address of the device from which the Trap requests are sent. This is the same as the device key.

EXAMPLE: `ip: 192.0.2.2`

#### active

Whether a device is actively counting towards the license limit. This field may be manually changed as needed, however the license enforcer will always ensure the licensed number of devices are active.

* Default
  * `true`

#### last\_received

The datetime stamp of the last time a trap was received from the device. This field is used to determine if a device has not been heard from in a specified number of days and should be automatically deactivated.

EXAMPLE: `2024-09-29T00:11:04.876109-05:00`

As new devices send trap packets to the collector, an entry is automatically added to the device file. If the licensed count hasn't been reached, the device is set to active. Otherwise, users are free to update the file manually to specify which devices to listen for. As an added feature, NetObserv SNMP Trap will automatically deactivate a device that has not been heard from in a specified number of days.

### Configuration options

#### EF\_INPUT\_TRAP\_LISTENER\_DEVICE\_STORE\_TTL

This setting specifies how many days since last receiving a trap packet from a device to keep said device active. This ensures old devices are removed from the device store and do not count towards the licensed device count.

* Default
  * `30`

#### EF\_INPUT\_TRAP\_LISTENER\_DEVICE\_STORE\_CHANGE\_DETECTION\_ENABLE

When set to true, the device store will check for changes in the device store file every 10 seconds and automatically reload the device store when changes are detected. This means devices can be manually added or removed from the device store file without needing to restart the collector.

* Default
  * `true`


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