Cloud Agent as Passive Sensor

Overview

Qualys Cloud Agent as Passive Sensor (CAPS) is designed to detect and profile assets that are connected to your network in real time, without requiring credentials, active scans, or network configuration changes. CAPS monitors network traffic through mirrored ports or taps, identifying devices the moment they connect to your infrastructure.

This capability complements the Qualys Cloud Agent and scanner-based deployments by increasing asset visibility and helping close the blind spots in environments with unmanaged, transient, or rogue devices.

Core Benefits:

• Real-time discovery of assets entering or leaving the network
• Zero-touch deployment via network port mirroring (SPAN/tap)
• Enrichment of Qualys Global IT Asset Inventory
• Detection of unmanaged, unauthorized, or shadow IT devices

Who Should Use This Guide?

• Security Architects and Analysts
• IT Asset Managers
• Network Operations (NetOps) Teams
• Security Operations Center (SOC) Personnel

Before You Begin

• Passive Sensor appliances are correctly installed and connected to network ports
• Access to the Qualys Cloud Platform with appropriate user permissions
• CAPS is enabled in your Qualys subscription
• Cloud Agents are deployed to applicable endpoints (for enrichment correlation)

What You’ll Learn

• Understanding CAPS architecture and data flow
• Installing and configuring Passive Sensor appliances
• Integrating CAPS with Qualys Cloud Agent and IT Asset Inventory
• Viewing discovered assets in the Qualys UI
• Generating reports and setting alerts on unmanaged devices

Deployment Highlights

• Operates in passive mode; no IP address or credentials required
• Provides near-instant visibility into connected assets
• Integrates seamlessly with existing Qualys modules (AI, VMDR)
• Helps accelerate zero-trust and continuous monitoring initiatives

Related Resources

• Qualys Global IT Asset Inventory
• Qualys Passive Sensor Deployment Guide (PDF)
• Qualys Cloud Agent Overview

Need Help?

For help with architecture planning, integration strategy, or tuning discovery filters, contact your Qualys Technical Account Manager. You can also engage with the Qualys community  or reach out to Qualys Support for technical assistance.