Discovery - Classification criteria is missing/empty for OOTB Classifiers

[Suggy]

We know that

For each classifier, there will be classification criteria. That criteria contains the condition that a target host has to satisfy in order to trigger a relevant classifier. 

but for many OOTB classifiers, the criteria is empty.

Then how it works?

[doug_schulze · Accepted solution]

Via the SNMP SysOID, it calls the classifier.  

[VincentHua]

Hi Doug, would it be possible to share how to use Classification Criteria and its syntax, please? Indeed, I have some assets for which I don't have any matching OID. Therefore, I was thinking of using Classification Criteria instead of SNMP OID Classifications. Thank you.

[doug_schulze]

You would have to look at debug statement to see where all classification criteria you can use. I talk about its use here.  Or you can look at the snmp classify sensor to parse out all the values that can be set.  However in this case if you look at your snmp classify return for the device you should see the sysOID in that return but if thats empty then you would probably use 'sysDescr' contains <value> will probably suffice for what you are trying to do.

[VincentHua]

Hi Doug, thanks for your previous reply! I tried to apply what you recommended, but I am still struggling! 😉 Here is what my SNMP classification looks like:

The SNMP discovery returns 0 matching OID, but in the payload, "ip" is set, but how to use this variable as Classification Criteria?