Discovery of SNMP OIDs prototype

[Tex74]

Hi,

I try to work with SNMP discovery https://www.zabbix.com/documentation...snmp_oids_walk
Everything works fine until creating dependent item prototypes. I don't know what I'm missing:

1) I created the item:


It works fine and I get a result like this:
STORMSHIELD-HA-MIB::snsNbNode.0 = INTEGER: 2
STORMSHIELD-HA-MIB::snsNbDeadNode.0 = INTEGER: 1
STORMSHIELD-HA-MIB::snsNbActiveNode.0 = INTEGER: 1
STORMSHIELD-HA-MIB::snsNbHALinks.0 = INTEGER: 1
STORMSHIELD-HA-MIB::snsNbFaultyHALinks.0 = INTEGER: 1
STORMSHIELD-HA-MIB::snsNodeIndex.0 = INTEGER: 0
STORMSHIELD-HA-MIB::snsNodeIndex.1 = INTEGER: 1
STORMSHIELD-HA-MIB::snsFwSerial.0 = STRING: "XXX"
STORMSHIELD-HA-MIB::snsFwSerial.1 = STRING: "YYY"
STORMSHIELD-HA-MIB::snsOnline.0 = INTEGER: true(1)
STORMSHIELD-HA-MIB::snsOnline.1 = INTEGER: false(2)
....

2) Then I created my discovery rule:



Test works fine and I get:
[{"{#SNMPINDEX}":"0","{#SN.SERIAL}":"XXX","{#SN. ONL INE}":"1","{#SN.VERSION}":"ABC","{#SN.LICENCE}":"M aster","{#SN.HEALTH}":"Major"},{"{#SNMPINDEX}":"1" ,"{#SN.SERIAL}":"YYY","{#SN.ONLINE}":"2","{#SN. VER SION}":"","{#SN.LICENCE}":"Unknown"}]

3) Then I finaly create a dependent item prototype:



preprocessing: Tried different thing readed on the web. This last works in test mode with JSON in values.


My problem is that it doesn't work in real life, It seems my item prototype is using with what the early item returns (could be logical 'cause it's the master item...).
So, can anyone helps me finding what I'm missing. I don't know how to refer to discovery macros in this dependent item prototype

Thanks a lot

[Tex74]

HI,

I finaly find out.
As I said, it couldn't be anything else than a misunderstand of how things work.

So, the dependant Item preprocessing must be configure as a "value of SNMP walk" with the OID as parameter.

Hope this help...

[Tex74]

Sorry, I forgot to post the error:


Without preprocessing in item prototype, it returns the whole early item without error.

[Tex74]

Hi all,

No one to explain how to use lld macro in item prototype?
I am surely turning around a so simple solution.

Thanks in advance

[PZakrzewski]

Hi,

It seems the issue lies in the way the dependent item prototypes are handling discovery macros. Here are some key points to check:

1. Discovery Macros: Ensure the item prototype uses the correct discovery macros like {#SNMPINDEX} in its key and preprocessing steps. Macros are resolved only during runtime for each discovered entity.
2. Preprocessing: Use “JSONPath” or “Regex” to extract specific values. Example JSONPath:

$[?(@["SNMPINDEX"] == "{#SNMPINDEX}")].snsFwSerial

Replace snsFwSerial with the desired OID.

3. Test Preprocessing: Use the “Test” button in the item prototype to confirm that the macros resolve correctly and return the expected values.
4. Master Item Relation: Ensure the prototype is linked to the discovery rule, as macros won’t work outside its context.

If you still face issues, please share the exact error or logs for further assistance.
Cheers!

[Tex74]

Hi,

Thanks for your reply.

"Ensure the prototype is linked to the discovery rule": As my Item prototype has been created inside a discovery rule, It is linked, yes?
I can't see another way inside the prototype to link it to the discovery rule. It's a dependent item and the master item is the first one I made. The one that results the snmp walk.

To resume:
1. An Item "HA INFO", SNMP agent with a walk. The result is:

.1.3.6.1.4.1.11256.1.11.1.0 = INTEGER: 2
.1.3.6.1.4.1.11256.1.11.2.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.3.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.5.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.6.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.7.1.1.0 = INTEGER: 0
.1.3.6.1.4.1.11256.1.11.7.1.1.1 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.7.1.2.0 = STRING: "XXX"
.1.3.6.1.4.1.11256.1.11.7.1.2.1 = STRING: "YYY"
.1.3.6.1.4.1.11256.1.11.7.1.3.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.7.1.3.1 = INTEGER: 2
.1.3.6.1.4.1.11256.1.11.7.1.4.0 = STRING: "TOTO"
.1.3.6.1.4.1.11256.1.11.7.1.4.1 = ""
.1.3.6.1.4.1.11256.1.11.7.1.5.0 = STRING: "A.B.C"
.1.3.6.1.4.1.11256.1.11.7.1.5.1 = ""
.1.3.6.1.4.1.11256.1.11.7.1.6.0 = STRING: "Master"
.1.3.6.1.4.1.11256.1.11.7.1.6.1 = STRING: "Unknown"

2. A discovery rule, dependent item of master item "HA INFO", with a preprocessing "SNMP to JSON". The result is:

[{"{#SNMPINDEX}":"0","{#SNSERIAL}":"XXX","{#SNONLINE}":"1","{#SNVERSION}":"A.B.C","{#SNLICENCE}":"Master"},{"{#SNMPINDEX}":"1","{#SNSERIAL}":"YYY","{#SNONLINE}":"2","{#SNVERSION}":"","{#SNLICENCE}":"Unknown"}]

3. A item prototype, dependent item of master item "HA INFO", with a preprocessing "JSONPath"
In test mode, parsing the discovery result, with this syntax:

$[?(@["SNMPINDEX"] == "{#SNMPINDEX}")].1.3.6.1.4.1.11256.1.11.7.1.2.0

I get

cannot extract value from json by path "$[?(@["SNMPINDEX"] == "{#SNMPINDEX}")].1.3.6.1.4.1.11256.1.11.7.1.2.0": no data matches the specified path

Without preprocessing, the prototype creates an item that returns the all master item result. That's also the reason I have items where I can see that {#SNMPINDEX} is working for item name and item key:


(This means that the macro I want as a value could be writen in the item name withaout any problem. Crazy isn't it?)

With any preprocessing, the error is:

Preprocessing failed for: .1.3.6.1.4.1.12345.1.11.1.0 = INTEGER: 2..1.3.6.1.4.1.11256.1.11.2.0 = INTEGER: 1..1.3.6.1.4.1.11...
1. Failed: cannot extract value from json by path "$[?(@["SNMPINDEX"] == "1")].1.3.6.1.4.1.11256.1.11.7.1.2.0": invalid object format, expected opening character '{' or '[' at: '.1.3.6.1.4.1.11256.1.11.1.0 = INTEGER: 2
.1.3.6.1.4.1.11256.1.11.2.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.3.0 = INTEGER: 1
.1.3.6.1.4.1.11256.1.11.5.0 = INTEGER: 1

This lets me think that prototype works with the master item result and not the discovery result.
This goes back to "Ensure the prototype is linked to the discovery rule"....

Thanks for helping

[Tex74]

HI,

I finaly find out.
As I said, it couldn't be anything else than a misunderstand of how things work.

So, the dependant Item preprocessing must be configure as a "value of SNMP walk" with the OID as parameter.

Hope this help...