---
sourceDocument: Brazil IT Operations Management
sourceDocumentLink: https://www.servicenow.com/docs/r/it-operations-management

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    - brazil

ft:locale :

    - en-US

ft:publication_title :

    - Brazil IT Operations Management

ft:clusterId :

    - itom

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workflow :

    - Technology


---

# Exploring Discovery

# Exploring Discovery {#ariaid-title1}

Release version: Brazil  
Updated September 10, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 5 minutes to read
Summarize  
![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI  
This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.  

## Summary of Exploring Discovery

Discovery in ServiceNow identifies computers, servers, printers, IP-enabled devices, and related applications on your network.
It updates your Configuration Management Database (CMDB) with this data, enabling accurate asset and service management.
Discovery operates primarily through two methods: horizontal discovery, which scans the network to find and relate configuration items (CIs) directly, and top-down discovery (Service Mapping), which maps CIs within business services to show their interdependencies.
Show full answer Show less  

## Key Features

* **Horizontal Discovery:** Scans the network to identify devices and applications, creating direct CI relationships like "runs on" connections. It does not map business service relationships.
* **Top-down Discovery:** Used by Service Mapping to identify and map CIs as part of business services, illustrating relationships between components like web servers and databases.
* **Probes and Sensors:** Scripts that collect and process data from devices. Probes perform data collection, and sensors parse the returned data to update the CMDB. These can be customized or created to extend functionality.
* **Patterns:** Written in Nebula Discovery Language (NDL), patterns are advanced sequences of operations triggered in later discovery phases to collect detailed CI data and relationships. They can be customized using the Pattern Designer.
* **MID Servers:** Act as secure intermediaries that execute probes and patterns, communicate with devices using standard protocols (SSH, SNMP), and return data to the ServiceNow instance. MID Servers require no agents on target devices and initiate all communication securely inside the firewall.
* **Types of Discovery:**
  * Network Discovery: Identifies internal IP networks.
  * CI Discovery: Standard discovery of devices, computers, and applications.
  * Cloud Discovery: Finds resources in AWS and Azure clouds.
  * Serverless Discovery: Discovers applications on hosts without discovering the host first, relying on patterns.
* **IP Service Affinity:** Stores successful IP service protocols used to discover devices, allowing Discovery to target devices efficiently in future runs by prioritizing the known successful protocol.

## Horizontal Discovery Process

Horizontal discovery proceeds in four phases:

* **Scanning:** A Shazzam probe detects open ports on devices to determine device types.
* **Classification:** Additional probes identify device types and operating systems using classifiers that trigger subsequent probes or patterns.
* **Identification:** Discovery gathers detailed device data and matches or creates CIs in the CMDB using identification rules.
* **Exploration:** Further probes collect detailed attributes and establish relationships between devices and applications, or patterns perform these actions if used.

## Benefits for ServiceNow Customers

By leveraging Discovery, customers can maintain an accurate and up-to-date CMDB without installing agents on each device. The flexible use of probes, sensors, and patterns allows tailored data collection to match organizational needs. Integration with Service Mapping enables clear visualization of business service dependencies, enhancing impact analysis and operational efficiency. The MID Server architecture ensures secure, agentless data collection within enterprise environments without complex firewall or VPN configurations.  
Discovery finds computers, servers, printers, a variety of IP-enabled devices, and the applications that run on them. It can then update the configuration items (CIs) in your Configuration Management Database (CMDB) with the data it collects.

## Horizontal discovery and top-down discovery {#c_GetStartedWithDiscovery__section_bfk_n1g_ycb}

There are two types of discovery:

Horizontal discovery

:   Horizontal discovery is a technique that Discovery uses to scan your network, find computers and devices, and then populate the CMDB with the CIs it finds. Horizontal discovery creates direct relationships between CIs, such as a `runs on` relationship between an application CI and the
    actual computer CI that it runs on. Horizontal discovery is not aware of business services and does not create relationships between CIs based on the business service they are in.

Top-down discovery

:   Top-down discovery is a technique that Service Mapping uses to find and maps CIs that are part of business services, such as an email service. For example, top-down discovery can map a website business service by showing the
    relationships between an Apache
    Tomcat web server service, a Windows server, and the MSSQL database that stores the data for the business service.

    Typically, Service Mapping and Discovery work together to run horizontal discovery first to find CIs, and then top-down discovery to establish the relationships between business services that you need to know.

## Probes, sensors, and patterns {#c_GetStartedWithDiscovery__section_xqk_wlt_jkb}

Discovery uses these components to find CIs:

[Probes and sensors](https://www.servicenow.com/docs/Xn_MIDuSkVzKiv3X_zWYDw "The horizontal discovery process passes through the four phases of discovery using probes, which gather information on the target machine. Sensors then help Discovery determine what to do with that information.")
:   Probes and sensors are scripts that collect and process data on a host and then update the CMDB. More specifically, probes explore or investigate CIs on your network, and sensors parse the data returned from the probes. Several probes and sensors are provided by
    default, but you can customize them to find different information, or you can create ones. You can also configure several parameters to control the behavior of a particular probe every time it is triggered.

[Patterns](https://www.servicenow.com/docs/JChX4mGFKEFvdrtwJW1r5g "Horizontal discovery with patterns has four phases, just as horizontal discovery with probes does. However, for the last two phases, Discovery triggers operations from a pattern, rather than additional sets of probes.")
:   Patterns, like probes and sensors, are a series of operations that also collect data on a host, process it, and update the CMDB. Patterns differ from probes and sensors in that they are written in Neebula Discovery Language (NDL) rather than JavaScript, and they are called into action in the later stages of the horizontal discovery process. Default patterns are provided, but you can also customize or
    create patterns using the Pattern Designer.

## Horizontal discovery phases {#c_GetStartedWithDiscovery__discovery-phases}

The phases of horizontal discovery are:  
Discovery follows these phases:

Scanning
:   Discovery sends a probe called Shazzam to the network to see if commonly used ports are open
    and if these ports can respond to queries. For example, if Shazzam finds a device that responds on port 135, Discovery knows that it's a Windows server.

Classification
:   If Discovery finds devices or computers, it sends additional probes to find the type of device or the
    operating system on the device. For example, Discovery sends the WMI probe to a Windows machine to detect the Windows 2012 operating system. Then Discovery uses records called classifiers, which specify the trigger probe or probes that run
    during the next two phases. If you're using patterns, the classifier specifies a trigger probe that in turn launches a pattern.

Identification
:   Discovery tries to gather more information about the device and then tries to determine if a CI for the
    device exists in the CMDB. Discovery then uses additional probes, sensors, and identifiers to update existing CIs in the CMDB or
    create new ones. Identifiers, also known as identification rules, specify the attributes that the probes look at when reconciling data with the CIs in the CMDB. If you're using patterns, Discovery uses the appropriate identification rule for the CI type specified in the pattern.

Exploration
:   The identifier launches additional probes configured in the classifier. These probes gather additional information about the device, including the applications running on it and attributes such as memory, network cards, and drivers. Discovery then creates relationships between applications and devices and between applications. If you're
    using patterns, the operations in the pattern perform the exploration of the CI.

## Discovery communication through MID Servers {#c_GetStartedWithDiscovery__section_lb1_fdl_f2b}

A [MID Server](https://www.servicenow.com/docs/access?context=mid-server-landing&version=brazil&pubname=brazil-servicenow-platform&ft:locale=en-US), which constantly queries the instance for probes to run, executes the instructions in the probe or in the pattern that the probe specifies. The MID Server then returns the results to the instance, where sensors process it. The MID Server does not retain any discovery information.

The MID Server starts all communications, using SOAP on HTTPS, which means that all communications are secure, and all communications are initiated inside the enterprise's firewall. No special firewall rules or
VPNs are required.

Because Discovery is agentless, meaning that it does not require any permanent software to be installed on any computer or device to be discovered, the MID Server uses several techniques to probe devices without using agents. For example, the MID Server uses SSH to connect to a Unix or Linux computer, and then it can run a standard command, as specified in the probe, to gather information. Similarly, it uses the Simple Network Management Protocol (SNMP) to gather information from a network
switch or a printer.

## Types of discovery {#c_GetStartedWithDiscovery__section_lvj_5gl_f2b}

The types of horizontal discovery that the Discovery application can perform are
explained in the following table:  
{#c_GetStartedWithDiscovery__table_b2w_1hl_f2b__entry__2}

| Type | Description |
|-|-|
| Network discovery | Run this type of discovery to find the internal IP networks within your organization. If you already know the IP address ranges in your network, it is not necessary to run network discovery. |
| CI discovery | Run this type of discovery to find the devices, computers, and applications on your network. This is essentially the standard type of discovery that you run most often. |
| Cloud discovery | Run this type of discovery to find AWS and Azure resources in your organization's cloud. |
| Serverless discovery | Run this type of discovery to find applications on host machines without the need to discover the host first. Serverless discovery relies on patterns to explore CIs on a host. |
[ ]

{#c_GetStartedWithDiscovery__table_b2w_1hl_f2b}

## IP service affinity {#c_GetStartedWithDiscovery__section_rwp_y3v_5bb}

IP Service affinity saves the IP service information that is used to successfully find a
device and associates it with the IP address of the device. Using this information, Discovery can target the device in
subsequent runs with the accurate protocol. Discovery records the IP Service along
with the IP address. Discovery can
store the successful IP service information in the IP Service Affinity table
\[ip_service_affinity\].

For example: A network device has both an SSH port and an SNMP port open. By its agentless
design, Discovery tries SSH first.
However, network devices should be discovered through SNMP. Discovery tries the SSH probe and it
fails. This triggers the SNMP probe, which succeeds. With the association between the IP
address and the IP service, subsequent discovery runs that target this IP address use SNMP
first, because that is the probe that succeeded.
* **[Horizontal discovery process flow with probes and sensors](https://www.servicenow.com/docs/Xn_MIDuSkVzKiv3X_zWYDw)**   
  The horizontal discovery process passes through the four phases of discovery using probes, which gather information on the target machine. Sensors then help Discovery determine what to do with that information.
* **[Horizontal discovery process flow with patterns](https://www.servicenow.com/docs/JChX4mGFKEFvdrtwJW1r5g)**   
  Horizontal discovery with patterns has four phases, just as horizontal discovery with probes does. However, for the last two phases, Discovery triggers operations from a pattern, rather than additional sets of probes.

**Related concepts**   

* [Discovery setup](https://www.servicenow.com/docs/gWx0E2lktIJXxDxSvCF6CQ "After you activate the Discovery application, you have several ways to get started.")
* [Discovery monitoring and issue resolution](https://www.servicenow.com/docs/vFxqQxy0eeYJCxsG9NsBug "Learn how to monitor the progress of your discoveries and how to configure the system to aggregate performance metrics that are important to you. Find descriptions of the error messages you see, and possible steps you can take to solve problems. The Now Support Knowledge Base on Hi contains several articles to help you troubleshoot discovery issues.")

