Device Group Criteria and Device Custom Fields

Device Groups offer the flexibility to specify custom fields data as matching information against custom fields identification values defined on individual devices. You specify custom fields information in device groups through the Device Group Criteria. Doing so, you can craft device groups that match specific types of information, such as Business Units, operational function, and so on. Based on the information in the section Defining and Using Custom Fields, you can create device custom fields (“device” is a specific type of custom field that you can create and use for data matching) that are referenced by specific device groups for collection of devices into logically-named groups in NetMRI for asset manageability.

Supporting custom fields in device groups requires some specific Device Group Criteria syntax. Because a custom field can use the same nomenclature as a standard device attribute (for example, the Custom Fields feature does not prevent you from creating a custom field named “Type,” “Vendor” or “Model”), the device group criteria uses a convention to prevent conflicts. To do so, you prefix every Device Group Criteria reference to a device custom field with a syntax constant:

$custom_

Consider the creation of a device custom field called “business_unit.” For information on how to create custom fields in NetMRI, see Defining and Using Custom Fields. Editing the Device Group Criteria field for a device group called “Consumer Banking Group” to support a device custom field, the typical syntax is as follows:

$Assurance > 65 and $Type in ["Router","Switch-Router",”Switch”,”Firewall”] and $custom_business_unit = "Consumer Banking"

You prepend the constant $custom_ to the value “business_unit” to create the expression $custom_business_unit = “Consumer Banking”. Doing so in the Device Group Criteria ensures that any device that possesses a matching field value will match the “Consumer Banking Group” device group.