• Created by Unknown User (robert.dzido@infodesign.pl), last updated by Unknown User (aleksandra.luszowska@infodesign.pl) on Dec 06, 2017 3 minute read

Protocol Overview

SNMP (Simple Network Management Protocol) is an Internet-standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks and more. Read more on Wikipedia.

Implemented features

Currently SNMP protocol allows you to add an SNMP device which monitors queries and then reads and parse its result. For example, you can query your printer status/check ink or the toner level or just do a server health check.

SNMP queries use MIB trees to ask a device for a particular setting or status. For example, the OID 1.3.6.1.2.1.25.3.5.1.1.1 stands for the current printer status (in Printer-MIB). Different devices may have a different OID meaning. More details may be found in your device documentation or after contacting with the manufacturer. 

Protocol settings

Examples

Below you can find some screenshots showing a typical configuration. Please note that it can vary depending on your device vendor and model. We recommend to check SNMP queries and results using an external software (like an Open Source Net-SNMP) before implementing your service monitor.

Printer Health Check

Below you can find a Printer Status Check.

The Net-SNMP query and result (the printer available under 192.168.1.106 IP address queried from a Windows host, the SNMP version 2 is in use and the community name allowed by the device is "public")

snmpget.exe -v2c -Of -c public 192.168.1.106 1.3.6.1.2.1.25.3.5.1.1.1
.iso.org.dod.internet.mgmt.mib-2.host.hrDevice.hrPrinterTable.hrPrinterEntry.hrPrinterStatus.1 = INTEGER: idle(3)

If you imitate properties listed above in PULSE - Monitoring Tool for JIRA SNMP protocol, you will get a "3" as result of the query. Net-SNMP allows you to specify the output. If you want to display only the returned value (without the MIB tree), you can use the "-Ov" parameter. In that case the output will look like shown below:

snmpget.exe -v2c -Ov -c public 192.168.1.106 1.3.6.1.2.1.25.3.5.1.1.1
INTEGER: idle(3)


By default the SNMP protocol port is UDP 161 and if you will not set a port value during the setup, it will be set to the default value. 

If every time you test your SNMP service, you get a notification about an unreachable host it is worth to check if:

  • the community name is correct,
  • the host address is correct,
  • the tested device is in the same network as you are,
  • the specified protocol version is correct (remember that 3rd version of SNMP protocol is NOT available in PULSE - Monitoring Tool for JIRA yet),
  • the port is the default port or is the same as the tested device.

If your SNMP service returns the "NULL" value, there are two options possible:

  • the OID you have used is invalid,
  • the SNMP server returns a non-numerical value (i.e date/time). 
     

Important

Currently PULSE - Monitoring Tool for JIRA supports only numerical values returned by SNMP queries. It allows you to define "correct' or "expected" values and check if they match your definition. If not - the test result will be marked as failure. In the case with the SNMP protocol returning a text value, it will be thrown as a service state description. You can always check the returned value by executing a test of the specified service.



  • No labels