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

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 Modle 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

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 router configuration and status information variables. Download the MIB file and upload/load it in MIB browser.

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.

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, upload/load MIB file. MIB browser lets you walk through all OID codes, or return a distinct variable value.

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.

Trap rules

Trap rules describe on what event SNMP agent should send Trap messages.