Enabling SNMP on Windows Hosts

All that's a lot to digest, so let's enable the SNMP agent on a Windows system and see what it can do for us. To enable the SNMP agent on Windows XP, follow these steps.

1. Navigate to Start | Settings | Control Panel.
2. Open Add or Remove Programs
3. Select Add/Remote Windows Components on the left side of the window.
4. Highlight Management and Monitoring Tools, but do not check it.
5. Click Details.
6. Place a check next to Simple Network Management Protocol and click OK.
7. Click Next and then click Finish.

Next you need to configure some specific SNMP settings on the Windows host. Do this by following these steps.

1. Click Start | Run and enter services.msc to open the services snap-in.
2. Double-click the SNMP Service entry in the right pane.
3. Select the Agent tab.
4. Enter the Contact information and the Location information. These are used as identifiers for the system when viewed from the management console.
5. Open your MMC.
6. Select Computer Management in the left pane.
7. Expand this to Computer Management | Services and Applications | Services.
8. In the Service section, place a check next to the types of SNMP MIBs you want to use.
9. Select the Traps tab.
10. In the Community name drop-down list, enter a community name, also called a community string, and then click Add to list.A community string is very much like a password and serves to limit who can use SNMP on a given device.
11. In the Trap Destinations section, click Add and enter the system you want to send traps to.This would be the SNMP management console.To use a previous example, this could be the IP address of the system running PRTG Traffic Grapher.
12. Select the Security tab.
13. Highlight the default community name of public and click Remove. If you leave public as a READ ONLY community, anyone will be able to read the SNMP data of your system.The default on most systems is "public" with read-only access and "private" with full control. As is always the case, you don't want to use the defaults when it comes to passwords.
14. Click Add and enter a Read Only Community Name, and click Add again.
15. Repeat this process and add a community name with read/write access.
16. Select the radio button next to Accept SNMP packets from these hosts and click Add.
17. Enter an IP address or host name and click Add. In this example entered the same IP as my PRTG management console.
18. Click Apply and OK.

Your Windows system is now ready to be managed using SNMP; all you need is a management console. In this case we can add it as an additional sensor to our PRTG system (remember the freeware version has a limit of three sensors).To add the Windows host to your PRTG console, follow these steps.

1. Open the PRTG application.
2. In the Sensors pane, highlight All Sensors.
3. Right-click and select Add Sensor.This will start the Add Sensor Wizard.
4. Click Next.
5. Select SNMP as your data acquisition type and click Next.
6. The default selection of Standard Traffic Sensor will enable you to see how much bandwidth is being used by the Windows system inbound and outbound.The SNMP Helper Sensor will enable you to view some more-detailed Windows-specific counters. For basic monitoring select Standard Traffic Sensor and click Next.
7. In the Device Selection window, enter a name for the sensor and the IP address. Choose your SNMP version (choose the highest one your device will support). Enter the community string to use for that sensor, and then click Next. It will connect to the sensor and enable you to select which interface to monitor.
8. Place a check next to the appropriate interface.
9. Choose which values to monitor (Bandwidth is the default) and click Next.
10. This final screen enables you to choose a group for the sensor listing and configure the scanning interval.The defaults are probably okay, so simply click Finish.

You should see a new set of graphs, with bandwidth in and bandwidth out, for the newly added sensor.To add a sensor that uses the SNMP helper freeware, the steps are mostly the same.The only significant difference is that you need to run the Paessler SNMP Helper Setup.exe file on the system to be monitored.This setup file can be found in the same directory that PRTG was installed in.The setup file has no real configuration options and is very easy to install.

After installing the SNMP helper, proceed with adding the sensor following the steps above, with the following changes. When you select the type of SNMP to use, simply select SNMP Helper Sensor, choose the SNMP Helper Freeware in the drop-down box, and then click Next.The PRTG console will connect to the agent and present you with a list of all the possible values you can monitor. After making your selections, click Next.