Examples of Discovery behavior functionalities
Summarize
Summary of Examples of Discovery behavior functionalities
This guide explains how to configure Discovery behaviors in ServiceNow to efficiently scan multiple network domains and device types using MID Servers. It highlights the need for different functionalities based on protocol and domain constraints, especially for Windows environments where authentication limits scanning scope.
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Key Functionalities
- Functionality 1: WMI Scanning on Domain A
- Configures a Windows MID Server (e.g., sandb01-358) to scan Windows devices on Domain A via WMI.
- Requires specifying criteria to identify the MID Server and Windows domain.
- Uses phase 1 to launch a single Shazzam probe, maximizing efficiency.
- Only scans Windows machines within the MID Server’s own domain due to Windows authentication restrictions.
- Functionality 2: SSH and SNMP Scanning on Domain A
- Uses the same MID Server (sandb01-358) to scan for UNIX and SNMP devices.
- Excludes Windows (WMI) protocols to avoid duplicate classification.
- No specific criteria are needed for non-WMI functionalities.
- Also uses phase 1 to coordinate scanning efficiently.
- Functionality 3: WMI Scanning on Domain B
- Configures a second Windows MID Server (e.g., disco-win2003) to scan Windows devices on Domain B.
- Requires criteria to specify the MID Server and Windows domain for Domain B.
- Also set to phase 1, allowing a single Shazzam probe to cover all functionalities in this phase.
- Necessary because Windows authentication restricts WMI scanning to the MID Server’s domain.
Practical Considerations for ServiceNow Customers
- Windows MID Servers can only perform WMI scans within their own Windows domain, so separate functionalities and MID Servers are needed for each domain.
- SSH and SNMP scanning can be performed by Windows MID Servers across domains, but must be defined in separate functionalities to avoid mixing protocols.
- Using a single phase for all functionalities initiates one Shazzam probe, improving scan efficiency.
- Setting match criteria for WMI functionalities ensures targeted scanning by domain and MID Server, preventing redundant scans.
- Enabling the Active checkbox is essential to activate each functionality within the Discovery behavior.
By following this approach, customers can accurately scan Windows and non-Windows devices across multiple domains without redundant classifications, while leveraging MID Server capabilities and respecting authentication constraints.
This example of a Discovery behavior requires three functionalities for the behavior.
- A Windows MID Server can only discover Windows machines on the Windows domain to which it is joined. This is entirely due to the way Windows authentication works. For this reason, we need a WMI functionality for each domain.
- A Windows MID Server, provided with the correct credentials, can discover SSH and SNMP devices anywhere; however, we cannot combine WMI, SSH, and SNMP functionalities across Windows domains. This is because the functionality criteria for the WMI scans locks in the Discovery to one specific domain. For this reason, SSH and SNMP discoveries require a separate functionality.
- We want to scan each machine only once.
Functionality 1: WMI Scanning on Domain A
We configure a MID Server to scan for the WMI protocol on Domain A. WMI scans authenticate on Windows machines using the domain credentials of the Windows MID Server machine. Windows MID Servers cannot scan for the WMI protocol outside their own domains.
| Field | Input Value |
|---|---|
| Phase | Type a phase number of 1 in this field. All functionalities in this example use the same phase number, which launches a single Shazzam probe for all the functionalities in that phase. A single phase, when feasible, is the most efficient use of the Shazzam probe. |
| Functionality | Select Windows, DNS, and WINS from the list. This functionality defines the WMI protocol that will be scanned and resolves the domain. Because we selected to scan for WMI, we must select a Windows MID Server for this functionality. |
| MID Servers | We select a Windows MID Server from Domain A - in this case sandb01-358. |
| Active | Make sure this check box is selected to enable this behavior. |
| Match criteria | Change the criteria to All. |
Create Functionality Criteria
| Field | Input Value |
|---|---|
| Name | Create the following criteria:
|
| Operator | Select equals as the operator in this criteria. |
| Value |
|
| Active | Be sure to enable the criteria by selecting this check box (true). |
The completed criteria appear in the Discovery Functionality form for this behavior.
Functionality 2: SSH and SNMP
In our network, we want to scan for UNIX computers and netgear, but we don't want to classify these devices twice. One of our MID Servers will be configured to classify SSH and SNMP using a different functionality than it does for WMI scans. We do not need to create criteria for non-WMI functionality.
| Field | Input Value |
|---|---|
| Phase | Type a phase number of 1 in this field. All functionalities in this example use the same phase number, which launches a single Shazzam probe for all the functionalities in that phase. A single phase, when feasible, is the most efficient use of the Shazzam probe. |
| Functionality | Select All except Windows (no WMI) from the list. This functionality will scan SSH and SNMP protocols only. |
| MID Servers | We select the MID Server from Domain A - in this case sandb01-358. |
| Active | Make sure this check box is selected to enable this behavior. |
| Match criteria | Leave the default criteria of Any. Criteria are not used for non-WMI functionalities. |
Functionality 3: WMI Scanning on Domain B
All that remains is to create a functionality for the WMI scans on Domain B. Because of the Windows authentication mechanism, we must configure a Windows MID Server to scan Domain B that is a member of that domain.
| Field | Input Value |
|---|---|
| Phase | Type a phase number of 1 in this field. All functionalities in this example use the same phase number, which launches a single Shazzam probe for all the functionalities in that phase. A single phase, when feasible, is the most efficient use of the Shazzam probe. |
| Functionality | Select Windows, DNS, and WINS from the list. This functionality defines the WMI protocol that will be scanned and resolves the domain. Because we selected to scan for WMI, we must select a Windows MID Server for this functionality. |
| MID Servers | We select a Windows MID Server from Domain B - in this case disco-win2003. |
| Active | Make sure this check box is selected to enable this behavior. |
| Match criteria | Change the criteria to All. |
Create Functionality Criteria
| Field | Input Value |
|---|---|
| Name | Create the following criteria:
|
| Operator | Select equals as the operator in this criteria. |
| Value |
|
| Active | Be sure to enable the criteria by selecting this check box (true). |
The completed criteria appear in the Discovery Functionality form for this behavior.