What is the difference between the Target list and Target filter options for defining NAM monitor’s targets?

[GosiaMurawska]

What is the primary purpose of using a target list in NAM monitoring for hosts or devices that are not known to Dynatrace yet?

[Jacek_Janowicz · Accepted solution]

The target list is the only way of configuring NAM monitoring to be used for hosts or devices that are not known to Dynatrace yet, which means no One Agent deployed on hosts and no monitoring with Dynatrace extensions. It is recommended for devices where OA can't be deployed for technical reasons or organization limitations. You need to provide a single IP address/hostname or a list of them divided by commas, for example: 192.168.32.32, 192.168.32.38 

The Target filter approach is recommended for configuring the NAM monitoring for devices/hosts that are already known to Dynatrace, such as hosts on which OA is deployed (and configured as a host group) . In such a case, you may define the whole group as your target, and Dynatrace will ping all the interfaces of hosts belonging to the given group (optionally limited to the provided IP address range).  

Of course, you may also provide the IP addresses as a list. However, the extra benefit of the approach with the Target filter is that new hosts added to the host group are automatically known for NAM. That means those will be monitored with ping tests without any change in NAM configuration. 

Please notice that approaches with a Target list and Target filter might be combined within a single step of NAM monitor. In such a case, the target for NAM testing will be the sum of targets from those two fields. In other words, we do use logical OR between the Target list and the Target filter.

[bill_scheuernst]

For those entities which aren't known to Dynatrace through One Agent or an extension, would a custom device be similar, or even better? 

https://www.dynatrace.com/news/blog/add-custom-network-devices-with-just-a-few-clicks/

I would think a custom device would have more value for other use cases and not solely for NAM.  The custom entity would then be part of the DT ecosystem, smartscape, topology, Davis, etc.  Using a target address solely for NAM doesn't introduce the entity to DT and is only used for NAM; the entity ID would then only be for the NAM monitor, and not the individual IP or address.

[Jacek_Janowicz]

Hi @bill_scheuernst 
That's a very good point. I'm happy to share that this has already been addressed from the NAM perspective, as defining a Target filter based on Custom devices is supported.  
See https://docs.dynatrace.com/docs/shortlink/nam-monitor#examples

And I totally agree that registering, say, some network device in Dynatrace as a Custom device and then defining NAM monitor based on it is a valid and recommended way. My only doubt is linguistic here, after the registration, can we still call such a device unknown to Dynatrace? 

Still, the target list approach stays valid for cases when all you can (or want) to provide as a target for NAM is IP address of a device.

Best Regards, 

Jacek