SNMP configuration example

Summary

This chapter is a guide on configuring SNMP package to establish communication between devices.

SNMP

SNMP (Simple Network Management Protocol) - is widely used in networking management for networking monitoring. SNMP uses MIB (Management Information Base) to organize management data in the form of variables, which describe the system configuration and status.

Trap

Traps are alert messages sent by SNMP agent to SNMP manager.

SNMP agent - Teltonika router. Device which sends Trap messages to the manager.

SNMP manager - device which listens for Trap messages from the agents.

Teltonika routers are able to send SNMP Trap messages to the manager on their own when they experience a problem or a situation described in the rules.

Preconditions

RUT9xx

To setup SNMP first make sure that SNMP package is installed, more information here RUT955 Packages and RUT950 Packages.

OID codes

OID code (Object identifier code) - is an address used to identify devices and their status.

OID code is represented by the numbers in the boxes starting from "root".

Number	Label	Explanation
1	iso	ISO is the group that established the OID standard
3	org	An organization will be specified next
6	dod	The US Department of Defense (established the early internet)
1	internet	Communication will be via Internet/network
4	private	This is a device manufactured by a private entity
1	enterprise	The device manufacturer is classified as an enterprise
48690	Teltonika	Teltonika enterprise number

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To communicate with Teltonika router the start of the OID code, in this case, will be 1.3.6.1.4.1.48690.

Every configuration or status variable has distinct OID code.

Field	Number	Explanation
static	1	Static router information (Router name, Modem Imei, Modem model etc.)
gsm	2	Sim card information (Sim State, Operator, Mobile IP etc.)
hotspot	3	Hotspot information (Hotspot ip, users etc.)
Trap	4	Trap messages (Information sent through trap messages)
rut9x5	5	Input/Output information
gps	6	GPS information (Latitude, accuracy etc.)
ethernet	7	Information about router ports

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To access variable values, after enterprise number add field number and then specify variable number. For example: .1.3.6.1.4.1.48690.1.7.0 represents router name (48690.1.7.0: Enterprise (48690) - Teltonika, Field (1) - static, Variable (7.0) - routerName). All OID codes can be generated from MIB file, basic OID codes can be found here RUT955 SNMP#SNMP Variables list.

MIB File

MIB File can be used with MIB browsers for easier access to configuration and status information variables of the device. Download the MIB file and upload/load it in MIB browser. In this example iReasoning MIB browser was used only for testing purpose.

Generating OID code from MIB File

MIB File contains all OID codes. Line containing numbers needed for OID code can be identified by this marking "::=".

All that is left, is to add the numbers together. Example from given MIB File: 1.3.6.1.4.1.48690.1.1.0.

Important note: Do not forget to add .0 at the end of the generated OID code, except to Trap OID codes. Trap OID codes are only used by SNMP agent (router), using them in MIB browser or command line will not give any results.

SNMP Configuration

To configure SNMP, first enable SNMP service, leave or change the port, you can leave everything else as it is.

Press "Download" button to download MIB file.

Testing SNMP with MIB browser

Use MIB browser to test if SNMP works. Make sure to use same port and IP address of the router in MIB browser. To enter port number in MIB browser press "Advanced" button (on the right of IP address field).

To upload/load MIB file press "File" in menu bar (top left side of the window) and press "Load MIBs", make sure to select the MIB file you downloaded from the WebUI. MIB browser lets you walk through all OID codes, or return a distinct variable value. To walk through all OID codes select "walk" in Operation tab (top left of the window). To iterate through OID codes manually, navigate to the desired folder on the left of the MIB browser window and select specific element (Double click). The value of the variable will be printed in the Result Table.

Testing SNMP with console command

We can use snmpget command to get information from router:

$ snmpget -c public -v 2c IP_address:port OID_code

Example:

$ snmpget -c public -v 2c 192.168.1.1:161 1.3.6.1.4.1.48690.1.7.0

Trap Configuration

First enable SNMP Trap, then enter Host/IP, Hots/IP is the SNMP manager, computer to which SNMP agent will send Trap messages. If router is connected to PC via ethernet cable, enter the IP address of the interface the router is connected to. You can use ipconfig command on windows, ifconfig on linux to find IP address of the interface to which router is connected. Next choose port, preferably choose port number higher than 1024 so SNMP manager could establish connection without root/admin rights. If you choose to leave default port 162 make sure to launch SNMP manager with admin/root permissions.

Trap rules

Trap rules describe on what event SNMP agent should send Trap messages. There are certain rules which can be set up using Teltonika WebUI depending on physical configuration of the device.

Rule name	Value	Explanation
Signal strength trap	Minimal mobile signal strength	Teltonika device will send trap message when mobile signal strength falls lower than specified
Connection type trap	This trap does not have value	Teltonika device will send trap message when mobile connection establishes or changes
Digital input trap	Inactive/Active/Both	Teltonika device will send trap message when Digital input value changes to specified value
Digital isolated input trap	Inactive/Active/Both	Teltonika device will send trap message when Digital isolated input value changes to specified value
Analog input trap	Higher/Lower/Both + Voltage value	Teltonika device will send trap message when Analog input value fulfills specified requirement
Digital output trap	Inactive/Active/Both	Teltonika device will send trap message when Digital output value changes to specified value
Digital relay output trap	Inactive/Active/Both	Teltonika device will send trap message when Digital relay output value changes to specified value

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To create new rule chose action and press "Add" button, specify rule values and save.

Example: choose "Connection type trap" action and press "Add" button.

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Enable trap rule and press "Save".

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New rule should appear in the main Trap window.

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Testing Trap with MIB browser

To test trap messages with MIB browser, open Trap receiver and configure the setting. Make sure to use the same port saved in WebUI configuration.

Note: Preferably open MIB browser with root/admin permissions.

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To test "Connection type trap" reboot mobile modem. You can reboot modem through Status -> Network window. MIB browser should receive Trap message.