How to install SNMP extension agent DLL

• Download demo project - 15.6 Kb

Introduction

This tutorial is the second part of my previous article "How to develop a SNMP extension agent DLL".

Here I shall explain how to install the developed SNMP extension agent DLL in Windows 2000. This agent DLL is from the previous part of this article. Please find the source code of this DLL from the previous article. Here I'm demonstrating SNMP on the same computer, which will act as SNMP client and server (i.e., SNMP manager and Agent, respectively). Real thing should be on two computers. To install and experiment on the same computer, we don't need Internet connection. So in this case, we'll be using "127.0.0.1" local IP.

Install SNMP Service

By default, Windows 2000 doesn't have SNMP installed. Therefore, install the SNMP services first. For that, go to "Control panel", "Add\Remove Programs". Click "Add/Remove Windows components". Check the checkbox "Management and Monitoring Tools". Then on Detail, check "Simple Network Management Protocol". Click Next and complete the installation. Most probably, you will need Windows 2000 CD inserted to complete the installation.

After the installation, go to the Services and make sure you have two new services "SNMP Service" and "SNMP Trap Service". "SNMP Service" corresponds to the service file SNMP.EXE and "SNMP Trap Service" corresponds to the service file SNMPTRAP.EXE. You can find the Services Tool (Management Console Tool) in "Administrative Tools" under "Control Panel".

Configure Services

To configure, on Services (Management Console Tool), right click on "SNMP Service" and click "Properties". Properties dialog will open up. This will look like this...

Select the tab "Traps". Type "public" on "community name" combo box and click "Add to list" button. Then to fire traps to our same computer, click "Add" and add the IP address "127.0.0.1". If you have the luxury of another computer then specify its IP address here.

Now go to "Log On" tab and enable the "Profile 1" by clicking "Enable" button. Also make sure "Local system account" radio button appears selected.

Now to configure security, go to the tab "Security". Check the checkbox "Send authentication trap". Click "Add" under "Accepted community names". On appearing dialog box, select "READ WRITE" on "Community rights", enter "public" on "Community name", and click "OK". If you want to accept requests only from a particular client, then select "Accept SNMP packets from these hosts" and click "Add" underneath that. Type the host name or IP address and click "OK" on the appearing dialog box. After all this, click "Apply" or "OK" and close the "SNMP Service" Properties dialog. If the service is not started, right click and start it. Security tab will look like this...

After finishing "SNMP Service" configuration, select "SNMP Trap Service" and open up the Properties dialog by right clicking on it. On the "Log On" tab, configure as for the service before. Then "Apply" or "OK", and close the "SNMP Trap Service" Properties dialog.

These minimal configurations are enough to run our MyAgent.DLL. All your configurations will be stored under the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SNMP

Configure Our Agent

Now we have to configure our extension agent. We have to do this by adding registry entries in two places.

First, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SNMP\Parameters\ ExtensionAgents registry key using any registry editor. If you have installed the SNMP properly, then you can see several Microsoft agents' entries. What we have got to do is add a string value at the end of all agent entries and add our agent's registry key path. After adding, here is how my registry looks like...

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ 
                        Services\SNMP\Parameters\ExtensionAgents]
"1"="SOFTWARE\\Microsoft\\LANManagerMIB2Agent\\CurrentVersion"
"2"="SOFTWARE\\Microsoft\\RFC1156Agent\\CurrentVersion"
"3"="SOFTWARE\\Microsoft\\HostMIB\\CurrentVersion"
"4"="SOFTWARE\\Microsoft\\SNMPMIB\\CurrentVersion"
"5"="SOFTWARE\\Microsoft\\SNMP_EVENTS\\CurrentVersion"
"6"="SOFTWARE\\Microsoft\\ACS\\CurrentVersion"
"7"="SOFTWARE\\Microsoft\\IGMPMibAgent\\CurrentVersion"
"8"="SOFTWARE\\Microsoft\\IPMulticastMibAgent\\CurrentVersion"
"9"="SOFTWARE\\Microsoft\\IPXMibAgent\\CurrentVersion"
"10"="SOFTWARE\\Microsoft\\IASAgent\\CurrentVersion"
"11"="SOFTWARE\\SNMP\\CurrentVersion" <--<note, this is our agent's 
                                                reg path that I added>

Secondly, we should create the registry key path that we specified previously. Under this key, create a string value and name it as "Pathname" and put the actual DLL path. After adding, here is how my registry looks like...

[HKEY_LOCAL_MACHINE\SOFTWARE\SNMP\CurrentVersion]
"Pathname"="H:\\VC++ Dev\\SNMP\\MyAgent\\Release\\MyAgent.dll"

Test Our Installation and Agent

Now we are ready to test our installation and extension agent. I can hear you asking "what about client tool?". Yep, still I didn't mention any thing about client. There are three options available to you:

• Follow my next article "MIB Browser tool - Tool to traverse MIB tree using SNMP" and get the tool and test it.
• Download some free tool from the web to browse MIB tree (or if you are rich, buy one ;)).
• Create you own tool from SNMP walk through template class: C++ Template class to walk through a tree from Nandagopal.

Conclusion

I have written this article to make my extension agent-developing tutorial complete and to make it easy for beginners. Any way, you can find very detail explanation about Windows SNMP services and installations on MSDN "Getting Started with the SNMP Service" By James D. Murray.

Hope my article makes your life easy in learning SNMP. Thanks.