5 Откривање SNMP OID-а (застарело)

Преглед

У овом одељку ћемо извршити SNMP откривање на прекидачу.

Item key

Unlike with file system and network interface discovery, the item does not necessarily has to have an "snmp.discovery" key - item type of SNMP agent is sufficient.

To configure the discovery rule, do the following:

Go to: Data collection → Templates
Click on Discovery in the row of an appropriate template

Click on Create discovery rule in the upper right corner of the screen
Fill in the discovery rule form with the required details as in the screenshot below

All mandatory input fields are marked with a red asterisk.

The OIDs to discover are defined in SNMP OID field in the following format: discovery[{#MACRO1}, oid1, {#MACRO2}, oid2, …,]

where {#MACRO1}, {#MACRO2} … are valid lld macro names and oid1, oid2... are OIDs capable of generating meaningful values for these macros. A built-in macro {#SNMPINDEX} containing index of the discovered OID is applied to discovered entities. The discovered entities are grouped by {#SNMPINDEX} macro value.

To understand what we mean, let us perform few snmpwalks on our switch:

$ snmpwalk -v 2c -c public 192.168.1.1 IF-MIB::ifDescr
       IF-MIB::ifDescr.1 = STRING: WAN
       IF-MIB::ifDescr.2 = STRING: LAN1
       IF-MIB::ifDescr.3 = STRING: LAN2
       
       $ snmpwalk -v 2c -c public 192.168.1.1 IF-MIB::ifPhysAddress
       IF-MIB::ifPhysAddress.1 = STRING: 8:0:27:90:7a:75
       IF-MIB::ifPhysAddress.2 = STRING: 8:0:27:90:7a:76
       IF-MIB::ifPhysAddress.3 = STRING: 8:0:27:2b:af:9e

And set SNMP OID to: discovery[{#IFDESCR}, ifDescr, {#IFPHYSADDRESS}, ifPhysAddress]

Now this rule will discover entities with {#IFDESCR} macros set to WAN, LAN1 and LAN2, {#IFPHYSADDRESS} macros set to 8:0:27:90:7a:75, 8:0:27:90:7a:76, and 8:0:27:2b:af:9e, {#SNMPINDEX} macros set to the discovered OIDs indexes 1, 2 and 3:

[
           {
               "{#SNMPINDEX}": "1",
               "{#IFDESCR}": "WAN",
               "{#IFPHYSADDRESS}": "8:0:27:90:7a:75"
           },
           {
               "{#SNMPINDEX}": "2",
               "{#IFDESCR}": "LAN1",
               "{#IFPHYSADDRESS}": "8:0:27:90:7a:76"
           },
           {
               "{#SNMPINDEX}": "3",
               "{#IFDESCR}": "LAN2",
               "{#IFPHYSADDRESS}": "8:0:27:2b:af:9e"
           }
       ]

If an entity does not have the specified OID, then the corresponding macro will be omitted for this entity. For example if we have the following data:

ifDescr.1 "Interface #1"
       ifDescr.2 "Interface #2"
       ifDescr.4 "Interface #4"
       
       ifAlias.1 "eth0"
       ifAlias.2 "eth1"
       ifAlias.3 "eth2"
       ifAlias.5 "eth4"

Then in this case SNMP discovery discovery[{#IFDESCR}, ifDescr, {#IFALIAS}, ifAlias] will return the following structure:

[
           {
               "{#SNMPINDEX}": 1,
               "{#IFDESCR}": "Interface #1",
               "{#IFALIAS}": "eth0"
           },
           {
               "{#SNMPINDEX}": 2,
               "{#IFDESCR}": "Interface #2",
               "{#IFALIAS}": "eth1"
           },
           {
               "{#SNMPINDEX}": 3,
               "{#IFALIAS}": "eth2"
           },
           {
               "{#SNMPINDEX}": 4,
               "{#IFDESCR}": "Interface #4"
           },
           {
               "{#SNMPINDEX}": 5,
               "{#IFALIAS}": "eth4"
           }
       ]

Прототипови предмета

Следећи снимак екрана илуструје како можемо да користимо ове макрое у ставци прототипови:

Можете креирати онолико прототипова предмета колико је потребно:

Прототипови окидача

Следећи снимак екрана илуструје како можемо да користимо ове макрое прототипови окидача:

Прототипови графова

Следећи снимак екрана илуструје како можемо да користимо ове макрое прототипови графикона:

Резиме нашег правила откривања:

Откривени ентитети

Када се сервер покрене, он ће креирати стварне ставке, покретаче и графиконе на основу на вредности које враћа правило SNMP откривања. У конфигурацији домаћина имају префикс наранџасте везе до правила откривања до којих долазе из.

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