[HOWTO] Install and configure the Net-SNMP agent for Windows

[fmangeant]

• Version 0.2 (03/06/2008) : added a note about snmpd.conf file creation
• Version 0.1 (03/04/2008) : intial release

This HowTo will explain how to install and configure the Net-SNMP agent for Windows, as a "subagent" of the Microsoft SNMP agent, to graph the output of custom scripts.

As the time of writing, the latest version of Net-SNMP available is 5.4.1 (published on 07/27/2007).



Chapter I: Getting Net-SNMP binaries

Net-SNMP 5.4.1 for Windows can be downloaded here.
There's even an SSL version.

Once the file is downloaded, you just have to run the installer :



You then have to accept the license :



Next, you have to choose which type of agent you want to run :

• as a standard agent
• as a "subagent" of the Microsoft SNMP agent

Select the second option :



Next, choose an installation directory (C:\usr by default) :



Next, select an existing or a new Start menu folder :



The installer then copies the files :



Once installed, you have to register the Net-SNMP service





Chapter II: Configuring the Net-SNMP agent

The Windows SNMP service must be installed, but the service must be disabled.

Depending on where you've installed Net-SNMP, the main configuration file (snmpd.conf) will be located in <path>\etc\snmp (by default, C:\usr\etc\snmp).
The snmpd.conf has to be created.

Please note that you need to restart the "Net-SNMP Agent" service whenever you modify snmpd.conf !

The minimum configuration is this one :

Code: Select all

rocommunity public

Start then the "Net-SNMP Agent" service, and query it :

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C:\usr\bin>snmpwalk.exe -v 1 -c public localhost sysdesc
SNMPv2-MIB::sysDescr.0 = STRING: Hardware: x86 Family 6 Model 9 Stepping 5 AT/AT COMPATIBLE - Software: Windows 2000 Version 5.1 (Build 2600 Uniprocessor Free)

This OID got an anwser from the Microsoft SNMP service, whereas

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C:\usr\bin>snmpwalk.exe -v 1 -c public localhost versiontag
UCD-SNMP-MIB::versionTag.0 = STRING: 5.4.1

got an answer from the Net-SNMP agent.

At this point, you can use the "Windows XP/2000/2003" host template in Cacti, to graph CPU usage, disk drives usage, network bandwidth, etc.



Chapter III: Extending the Net-SNMP agent

A great functionnality of Net-SNMP is that you can "extend" it.

Let's run the C:\temp\foo.cmd script :

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C:\temp\foo.cmd
123

Now put this in snmpd.conf :

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exec foo c:\temp\foo.cmd

The result of your script will be accessible under the ucdavis.extTable.extEntry tree :

• output of the script : ucdavis.extTable.extEntry.extOutput
• exit status : ucdavis.extTable.extEntry.extResult
• command : ucdavis.extTable.extEntry.extCommand

You can check the result with this SNMP query :

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C:\temp>snmpwalk.exe -v 1 -c public localhost exttable
UCD-SNMP-MIB::extIndex.1 = INTEGER: 1
UCD-SNMP-MIB::extNames.1 = STRING: foo
UCD-SNMP-MIB::extCommand.1 = STRING: c:\temp\foo.cmd
UCD-SNMP-MIB::extResult.1 = INTEGER: 0
UCD-SNMP-MIB::extOutput.1 = STRING: 123
UCD-SNMP-MIB::extErrFix.1 = INTEGER: noError(0)
UCD-SNMP-MIB::extErrFixCmd.1 = STRING:

extOutput translates to .1.3.6.1.4.1.2021.8.1.101
As "foo" is our first exec directive, add ".1" at the end of the OID.

In Cacti, use the "SNMP - Generic OID Template" like this :

Voila ! Result of the C:\temp\foo.cmd script is now graphed in Cacti.

[elayaraja.s]

C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost sysdesc
Timeout: No Response from localhost

C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost versiontag
Timeout: No Response from localhost

[fmangeant]

Have you created snmpd.conf, and restarted the "Net-SNMP agent" service ?

[elayaraja.s]

Sorry, I am new to this SNMP. How to restart the Net-SNMP agent" service ?
I have searched in the Windows Serive not able to find...

[fmangeant]

Have you registered the service ?

[elayaraja.s]

1) I registered the serivice by executing registeragent.bat
2) C:\net-snmp\bin>net stop "net-snmp agent"
Output:The Net-SNMP Agent service was stopped successfully.
3) C:\net-snmp\bin>net start "net-snmp agent"
Output:The Net-SNMP Agent service was started successfully.
4) C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost versiontag
Output:Timeout: No Response from localhost
5) C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost sysdesc
Output:Timeout: No Response from localhost

Please check the output for the step 4 and 5.

[fmangeant]

Can you post the content of C:\net-snmp\etc\snmp\snmpd.conf ?

[elayaraja.s]

mibdirs C:/net-snmp/share/snmp/mibs
persistentDir C:/net-snmp/snmp/persist
tempFilePattern C:/net-snmp/temp/snmpdXXXXXX

Note: I dont have the folder name 'snmpdXXXXXX' under the path 'C:/net-snmp/temp/snmpdXXXXXX' remaining all fine.

[fmangeant]

C:\net-snmp\etc\snmp\snmpd.conf is a file which has to be created.

[elayaraja.s]

Now i have created the snmpd.conf file under the path C:\net-snmp\etc\snmp\snmpd.conf .

I restarted. Again same result.

But no need to worry about tempFilePattern C:/net-snmp/temp/snmpdXXXXXX (OR) i need to change to tempFilePattern C:\net-snmp\etc\snmp\snmpd.conf

[fmangeant]

I haven't modified the snmp.conf, and it works.

Is your Microsoft SNMP agent stopped ?

[elayaraja.s]

Yes it get stopped and started.

1) C:\net-snmp\bin>net stop "net-snmp agent"
The Net-SNMP Agent service was stopped successfully.

2) C:\net-snmp\bin>net stop "net-snmp agent"
The Net-SNMP Agent service was stopped successfully.

After creating C:\net-snmp\etc\snmp\snmpd.conf no need to modify right ? Its a blank file ?

[fmangeant]

You need to install Microsoft SNMP agent, and let it stopped.

C:\net-snmp\etc\snmp\snmpd.conf has to contain something like this :

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rocommunity public

[elayaraja.s]

C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost versiontag
Output: UCD-SNMP-MIB::versionTag.0 = STRING: 5.4.1

C:\net-snmp\bin>snmpwalk.exe -v 1 -c public localhost sysdesc
Output: No output.....Its blank..

[fmangeant]

Did you install Net-SNMP as screenshot #3 ?