# When to create a device template?

The device templates in OpManager contain predefined rules based on which a device is categorized and relevant monitors are associated soon after discovery. The ability to define custom templates for new device types or modify an existing template to accommodate yet another device type in the same template provides great flexibility to administrators.

OpManager includes over 18,500 device templates that provide the initial configurations required to classify devices into predefined types, significantly reducing deployment time. Out of these 18,500 templates, some are dynamically created and displayed by OpManager for certain devices based on the model information obtained during device discovery. If SNMP is enabled on the monitored devices, and if proper credentials are configured in OpManager, most devices fall into the correct category. However, you can further define custom templates or modify the existing ones to meet your environmental needs.

**1. When should I modify/update an existing template?**

Assume you have purchased a new Cisco 805 router and you would like to monitor it using OpManager. OpManager already has a device template for Cisco 800 series routers with few sysOIDs in these series updated in the template. All you need to do is edit this template to include the sysOID of Cisco 805 router if it is not present already.

Go to Configuration → Device Templates → Choose the desired device template → Click the Edit icon. In the Device Identifier section, click Add and enter an OID. Now, scroll to the bottom of the screen and press **Save** to save the changes.

[![Device template creation: Modify device templates](https://www.manageengine.com/network-monitoring/help/images/device-template-new-6.png)](https://www.manageengine.com/network-monitoring/help/images/device-template-new-6.png)

**2. When should I create new templates?**

**Scenario 1**

Let us now assume you have purchased a Cisco 11000 Series Content Services Switch. OpManager does not have a template yet (this is as of Build no.8721!). Just go ahead and create a new template.

**Scenario 2**

Assume you have a whole new set of Environment Sensors that are manageable (that supports SNMP). These devices cannot be classified under any of the default categories like servers, routers, switches etc, and deserve a separate category. The managing parameters too differ for this new device type. An ideal situation where you will define a new category view (Eg: Sensors) and define a fresh device template. You can have different models of sensors from the same vendor in a template or even combine Sensors from multiple vendors in the same template.

**Scenario 3**

Assume you are managing a set of Linux servers, where SNMP is disabled for security reasons. Here, using CLI device identifiers in device templates, you can discover Linux servers by selecting a CLI command from the Device Identifiers dropdown and specify a matching condition that compares an expected value with the command output.  
For example, by using the command **"cat /etc/*release | grep -E '^NAME|DISTRIB_ID'"** and specifying a matching condition (such as equals, starts with, or contains) that compares values like NAME="Ubuntu" or NAME="CentOS Stream" with the actual command output, OpManager can accurately detect the operating system and apply the correct device template for monitoring.

This is an ideal case for using CLI-based identifiers to create new templates. You can also create separate templates for different Linux distributions based on their CLI output.

**3. How to check for SNMP response to sysOID?**

Even before you proceed to add or modify a template to accomodate a new device type, make sure the device is SNMP enabled and it responds to query from OpManager. Invoke the MibBrowser utility bundled with OpManager to check for response. Let me show you how to check for SNMP response.

- From OpManager/bin, double-click to execute MibBrowser.bat.
- In the MibBrowser GUI, enter the device name, the SNMP port, and the read community string (default is PUBLIC).
- RFC1213 mib is loaded by default. Expand the mib to org->dod->internet->mgmt->mib2 ->system and select sysObjectID from this table.
- From the toolbar above, click on the Get SNMP Variable icon (7th icon from the left) to see the response in the text area to your right.

![Device template creation: MibBrowser.bat execution from OpManager/bin](https://www.manageengine.com/network-monitoring/faq/images/device-template1.jpg)

## Frequently asked questions:

1. [How do I configure device templates?](https://www.manageengine.com/network-monitoring/help/device-templates.html)
2. [How to classify two devices having same SysOID's into two separate Device Templates?](https://www.manageengine.com/network-monitoring/how-to/associating-same-sysoid-devices.html)
3. [Why the discovered device is categorized as Unknown?](https://www.manageengine.com/network-monitoring/faq/devices-discovered-as-unknown-devices-opmanager.html)
4. [How do vendor templates differ from device templates?](https://www.manageengine.com/network-monitoring/faq/difference-between-vendor-and-device-templates.html)
5. [How can I associate device templates to a newly discovered device?](https://www.manageengine.com/network-monitoring/help/associate-device-template.html)
6. [Why are some monitors not associated to the device while manually associating a device template?](https://www.manageengine.com/network-monitoring/faq/manually-classifying-associating-templates-opmanager.html)
7. [What is the difference between a device type and category?](https://www.manageengine.com/network-monitoring/kb/difference-between-device-type-and-category.html)
8. [How to import a new template obtained from ManageEngine Support or Community or a OpManager setup in different location?](https://www.manageengine.com/network-monitoring/how-to/import-template-from-community.html)
9. [How to display custom monitor value in dial via Show Dial option?](https://www.manageengine.com/network-monitoring/how-to/custom-dail-using-showdial.html)
10. [How to add bulk monitors to the Device Template?](https://www.manageengine.com/network-monitoring/how-to/add-bulk-custom-monitors-through-device-template.html)
11. [How to add device templates using CLI identifiers?](https://www.manageengine.com/network-monitoring/help/cli-device-identifier.html)