Discovering SNMP devices
Note: Some SNMP devices on your network may not adhere to RFC1213, causing them to remain undiscoverable even when your other settings are configured correctly. If you suspect this is occurring—or you want to discover SNMP devices that react to a very specific MIB—change the assigned device type to something more fitting (option seen in the lower-right of Figure 10). You may need to experiment with this setting if you are unsure of what to choose. Remember that RFC1213 is default.
We highly recommend allowing Observer to communicate with Simple Network Management Protocol (SNMP) enabled devices on your network. To do so, you must attempt to discover those devices automatically or add them manually. Observer SNMP functionality is only available with an Observer Suite license.
Note: This section only describes the process for automatic SNMP device discovery; to add SNMP devices manually (and perhaps with greater success than automatically) see Introduction to SNMP.
Before SNMP devices can be discovered, the IP discovery ranges must be configured. An error message is shown if you try discovering before the discovery ranges are configured.
Set the IP address discovery ranges by completing the following:
1. On the Home tab, in the Tools group, click SNMP > Device Discovery.
2. Click the Settings button. The SNMP Device Discovery window appears.
 
Figure 10: Configure SNMP IP discovery ranges
 
3. In the IP Ranges area, click Add to specify the IP discovery range. Repeat as necessary until all your IP discovery ranges are set.
4. In the SNMP Credentials area, click Add to configure an SNMP credential. Repeat as necessary until all of your possible SNMP credentials are listed.
The purpose of step 4 is to ensure the SNMP devices return a discovery handshake. Without providing credentials, SNMP devices may not react to your discovery attempts—overlooking devices that might otherwise have been discovered.
5. Click OK to save your changes. SNMP device discovery is now configured and discovery can be attempted.
6. Click Start to begin the discovery process.
7. As SNMP devices are discovered, select one from the list and click Add to SNMP Devices.
 
The SNMP devices you add are now recognized by Observer.