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Guardian
Learn how Guardian provides comprehensive asset inventory and network visibility for OT and IoT environments.
User Guide
Information and resources about the main features of Guardian, and the tasks that you can do from the user interface (UI).
Queries
You can use the Nozomi Networks Query Language (N2QL) syntax to create complex data processes to obtain, filter, and analyze lists of information from the Nozomi Networks software.
Examples
Join
An example query to join two data sources to obtain a new data source with more information. In particular, how to list the links with the labels for the source and destination nodes.

Guardian
Learn how Guardian provides comprehensive asset inventory and network visibility for OT and IoT environments.
- Introduction
  An overview of Guardian.
- Installation Guide
  Information and resources on how to install Guardian, and the different options and settings that are available.
- Administrator Guide
  Information and resources about the Administration section of Guardian, and the tasks that you can do in this part of the software.
- User Guide
  Information and resources about the main features of Guardian, and the tasks that you can do from the user interface (UI).
  - Sensors
    The Sensors page lets you view all of the sensors that you have in your system.
  - Alerts
    The Alerts page shows all the latest alerts in the system. It lets you view the alerts in different modes, and carry out actions on the alerts.
  - Assets
    The Assets page shows all the physical components and systems in the local network environment and their associated details. It also lets you perform actions on those assets. Depending on the nodes and components involved, assets can range from a simple personal computer to an operational technology (OT) device.
  - Queries
    You can use the Nozomi Networks Query Language (N2QL) syntax to create complex data processes to obtain, filter, and analyze lists of information from the Nozomi Networks software.
    - Data sources
    - Basic operators
    - Commands
    - Functions
    - Examples
      - Pie chart
        An example on how to create a pie chart to understand the media access control (MAC) vendor distribution in a network.
      - Column chart
        An example on how to create a column chart with the top nodes by traffic.
      - Where with multiple conditions in OR
        An example of a query to get all the nodes with a specific role, in particular all the nodes which are web or domain name server (DNS) servers.
      - Bucket and history
        An example of a query to calculate the distribution of link events towards an internet protocol (IP) address.
      - Join
        An example query to join two data sources to obtain a new data source with more information. In particular, how to list the links with the labels for the source and destination nodes.
      - Compute the availability history
        An example query to compute the availability history for a link.
      - Complex field types
  - Smart Polling in Guardian
    The Smart Polling page lets you view and manage Smart Polling.
  - Arc in Guardian
    Arc™ is a host-based sensor that detects and defends against malicious or compromised endpoints, and insider attacks. You can use Arc sensors to aggregate data for analysis and reports, either on-premises, or in the Vantage cloud.
  - Network
    The Network page gives you access to multiple pages that show nodes, links, sessions in tabular format and graphs and traffic in a graphical format.
  - Process
    Process is a set of repeatable functions that a business does to deliver a core value.
  - Reports
    The Reports page lets you manage, generate, schedule and view reports.
  - Assertions
    The Assertions page shows all the assertions and lets you configure them.
  - Time machine
    Time machine lets you load a snapshot, which is a previously saved state, and go back in time, to analyze the data from a past situation. You can load a single snapshot and use the platform as usual or load two snapshots and compare the user interface to highlight changes.
  - Vulnerabilities
    The Nozomi Networks software continuously discovers vulnerabilities in monitored assets.
  - Administration
  - Personal settings
    The personal settings page lets you do actions that are specific to your profile.
- Maintenance Guide
  Information about the maintenance tasks of Guardian, to help you administer and maintain the solution in a production environment.
- Print format documentation
  A list of all the print-format documentation that is available for Guardian.

Join

An example query to join two data sources to obtain a new data source with more information. In particular, how to list the links with the labels for the source and destination nodes.

You can match the from field of the links with the id field of the nodes to ask for the links, and join them with the nodes:

links | join nodes from id

After executing the query above you will get all the links fields, plus a new field called joined_node_from_id, it contains the node which satisfies the link.from == node.id condition. You can use the dot syntax to access the sub fields of joined_node_from_id

Because we also want to get the labels for the to field of the links you add another join and exclude the empty labels of the node referred by to to get more interesting data:

links | join nodes from id | join nodes to id | where joined_node_to_id.label != ""

This will obtain a huge amount of data, which is difficult to understand. To only get the relevant information, you can use a select:

links | join nodes from id | join nodes to id | where joined_node_to_id.label != "" | select from joined_node_from_id.label to joined_node_to_id.label protocol

Join example — Figure 1. Join example