Table of Contents - Paessler AG

1 2015 Paessler AGAll rights reserved. No parts of this work may be reproduced in any form or by any means graphic,electronic, or mechanical, including photocopying, recording, taping, or information storage and retrievalsystems without the written permission of the that are referred to in this document may be either trademarks and/or registered trademarksof the respective owners. The publisher and the author make no claim to these every precaution has been taken in the preparation of this document, the publisher and the authorassume no responsibility for errors or omissions, or for damages resulting from the use of informationcontained in this document or from the use of programs and source code that may accompany it.

2 In noevent shall the publisher and the author be liable for any loss of profit or any other commercial damagecaused or alleged to have been caused directly or indirectly by this : Oktober 2015 in NurembergSNMP Test er ManualContents3 Table of ContentsPart 1 Introduction51 About SNMP Tester62 SNMP The Simple Network Management Protocol73 Monitoring SNMP Devices: Troubleshooting9 Part 2 Download and Getting Started12 Part 3 Quick Start: Test SNM P with Sy stem UptimeRequest14 Part 4 Using SNM P Tester191 SNMP Settings212 Request Type243 Run SNMP Tester26 Part 5 Notes290 IndexPart 1: Introduction | 1 IntroductionWelcome to SNMP Tester, a free network tool for PRTG Network Monitor!

3 This tool is a testprogram indicated for debugging SNMP activities. It supports you in finding SNMP related issueswhen monitoring network devices with PRTG. The present document describes the underlyingconcepts and application fields for the SNMP tester, as well as it explains how to use the testerin SNMP Tester?Monitoring via SNMP is the most basic method of gathering bandwidth and network usagedata. However, SNMP as a base for extensive monitoring often comes not without for these issues are not obvious in many cases. The SNMP Tester is developed to support debugging steps for SNMP monitoring with can test various configurations to communicate with an SNMP device.

4 The tester recordsevery step of this communication so that you can investigate the functionality of your SNMP device and the corresponding SNMP 1: Introduction | 1 About SNMP Tester SNMP TesterThe SNMP Tester is a free network tool provided by Paessler for customers of PRTG NetworkMonitor. Mainly it is developed to have a tool available that enables you to debug SNMP activities down to the protocol level. The program is very useful if you encounter issues withPRTG and SNMP, especially when you contact our support team about these problems. With the tester you can run simple SNMP requests against an SNMP supporting device in yournetwork to debug your configuration.

5 For this purpose, the tool tries to establish an SNMP connection with the target device if this works, monitoring this device via SNMP is achievablein PRTG as v ia S NMP Works: S NMP CPU Load S ensorThe program is based on the SNMP technologies implemented in PRTG Network Monitor. Itcomes with various customizable settings so that you are able to test different configurationsfor SNMP monitoring. The SNMP Tester can optionally log packets of an SNMP request into a text file. This approachsupports you in finding communication and/or data problems in SNMP monitoringconfigurations.

6 With the created log file, you can analyze SNMP communication issues in moredetail. In addition, you can log raw data packets for debugging 1: Introduction | 2 SNMP The Simple Network Management Protocol The Simple Network Management ProtocolSNMP stands for Simple Net work Management Prot ocol. Monitoring with this technology isthe most basic method of gathering bandwidth and network usage data. Using SNMP, PRTG sends small data packages to devices for example, routers, switches and servers to queryfor traffic counters of each port. Furthermore, SNMP makes PRTG able to monitor othernetwork parameters, including CPU load, disk usage, temperature, and many other readings,depending on your Monitoring v ia S NMPI ntroduction to SNMPThe Simple Network Management Protocol (SNMP) was developed to get a standard formonitoring various devices.

7 This was necessary because of the huge amount of these deviceson the market, supplied by many different manufacturers. For monitoring, all available SNMP objects must have clear addresses to be accessible the OIDs which are stored in MIBs. SNMP requests are sent to these addresses to retrieve the desired detailed information about SNMP, please see section OIDs and MIBsTo access the values on a network device, the managing software needs to know theiraddresses. These addresses are called OIDs (Object Identifiers). They are organized in ahierarchical tree structure and defined in Management Information Base (MIB) files.

8 The nodesare defined by decimal numbers, separated by dots. A typical OID looks like this, an examplefrom an ISDN-MIB: With the SNMP Tester you can access theseaddresses directly if you provide specific Manual: Monitoring via SNMP Base: SNMP, MIBs and OIDs an 1: Introduction | 2 SNMP The Simple Network Management Protocol Paper: Quo Vadis SNMP? 1: Introduction | 3 Monitoring SNMP Devices: Troubleshooting SNMP Devices: TroubleshootingEvery so often customers using PRTG Network Monitor report issues when trying to monitortheir systems using SNMP. In most cases, these issues result from a malfunctioning SNMP configuration or installation.

9 The following section provides basics for monitoring via check this information in any case when problems with SNMP tioning S NMP S ensorNote: Before going any deeper into troubleshooting, a good knowledge of the principles andfunctions of SNMP is necessary. For references, please see section SNMP The SimpleNet work Management Prot RequirementsTo get monitoring via SNMP to work with PRTG, and to receive any results with the SNMPT ester, please ensure the following: Enable SNMP on the target device. Allow access t o SNMP for the machine running PRTG Network Monitor in the device'ssecurity settings.

10 Allow User Dat a Prot ocol (UDP) packages to travel from the machine running PRTG to thedevice you want to monitor and back. If the device and PRTG are on different sides of afirewall, make sure that UDP access t o port 161 (SNMP) is allowed. Import ant for firewall set t ings: SNMP requires the use of UDP ports >1023 to the PRTG client side. PRTG supports SNMP V1, SNMP V2c, and SNMP V3. You have to select a version in PRTG (andthe tester) which is supported by the device as 1: Introduction | 3 Monitoring SNMP Devices: Troubleshooting Aut hent icat ion must mat ch: You have to provide the correct community strings (SNMP V1and V2c), usernames (SNMP V3), and passwords (SNMP V3) in the tester respectively PRTG inorder to connect to an SNMP SNMP ActivitiesIf you encounter any problems with your SNMP sensors, the first step after checking basicrequirements is to debug SNMP activities.