If you cannot clearly see what is connected to your network, you risk working with an incomplete inventory. Unknown devices can go unmanaged, asset records can become outdated, and IT teams may struggle to know which devices actually need attention.
This is where the choice between agentless and agent-based discovery matters. In this article, we compare both approaches to see where each works best and which one fits your environment.
1. Agentless Discovery
What Is Agentless Discovery?
Agentless discovery is a method of identifying devices and collecting information about them without installing dedicated discovery software on each endpoint.
For example, an IT team can scan an office network and discover a printer at a specific IP address. The discovery tool may then identify the printer model and other available device details without installing anything on the printer.
How It Works
The discovery tool communicates with devices remotely through the network. Basic network discovery methods can detect active devices. They can also identify IP addresses and other basic information.
More advanced network discovery methods can collect deeper device details. These may include operating system information, hardware details, open ports, and device type.
This makes agentless discovery especially useful when IT teams need to understand what is connected to the network before every device is already known or managed.
2. Agent-Based Discovery
What Is Agent-Based Discovery?
Agent-based discovery collects device information through software installed directly on the endpoint.
For example, a company laptop has a discovery agent installed. The agent can continue reporting the laptop’s operating system, hardware, installed software, and device status. The agent can keep reporting this information even when the employee works from home or outside the corporate network.
How It Works
The agents gather information from inside the system and send it back to the network discovery or IT asset management platform. The device does not need to wait for a network scan to be found again. As long as the agent can communicate with the platform, it can continue reporting information even when the device is outside the corporate network.
Because the agents run on the endpoints, they can collect deeper and more consistent data than a network scan alone. This can include hardware details, operating system information, installed software, users, configuration, and device health.
3. Agentless vs Agent-Based Discovery at a Glance
Agentless and agent-based discovery solve the same basic problem: collecting information about IT devices. The main tradeoff is breadth versus depth.
Agentless discovery is easier to use across a wider range of devices, while agent-based discovery provides more consistent detail from managed endpoints. Here is how the two approaches compare across the areas that matter most.
Installation and Setup
Agentless discovery does not require software to be installed on every device. IT teams can start from a scanner or discovery server and scan a network range for reachable devices.
This makes it easier to begin when the existing inventory is incomplete. However, deeper agentless discovery may still require additional setup, such as credentials, permissions, or firewall configuration.
Agent-based discovery requires an agent to be installed on each endpoint first. This adds an initial deployment step, especially when many devices are involved. Once deployed, however, the agent can collect information directly from the device without repeatedly configuring remote access.
→ Agentless discovery is usually quicker to start, while agent-based discovery requires more upfront deployment.
Discovering Unknown Devices
Agentless discovery can scan a network to find devices not already recorded in the asset inventory. A responding IP address may reveal a forgotten laptop, a new printer, an unmanaged server, or another connected device.
Agent-based discovery generally cannot do this on its own. The software needs to be installed before the device can report itself. If IT does not know the device exists, there may be no agent on it in the first place.
→ Agentless discovery is better for finding unknown and unmanaged devices. Agent-based discovery is better suited to devices that IT already manages.
Device Coverage
Agentless discovery can work across a wider variety of network-connected assets. Besides computers and servers, it can discover devices such as printers, switches, routers, and IoT equipment.
Agent-based discovery is limited to devices that can run the agent. The device needs a compatible operating system, sufficient permissions, and a way to install and maintain the agent. This usually makes it a better fit for managed laptops, desktops, and servers than for printers or other network infrastructure.
→ Agentless discovery generally provides broader device coverage. Agent-based discovery focuses more on supported endpoints.
Level of Device Detail
Agentless discovery can range from very basic to quite detailed. A basic scan may reveal that a device exists on the network. More advanced methods can retrieve richer hardware and system details, depending on what access and permissions are available. The available data depends on network access, protocol support, credentials, and device configuration.
Agent-based discovery collects information directly from inside the endpoint. This typically gives it more consistent access to details such as hardware specifications, operating system versions, installed software, users, configurations, and device health.
→ Agentless discovery can provide useful detail, but the depth depends on the protocol and access available. Agent-based discovery is better when you need more consistent endpoint-level data.
Remote and Off-Network Devices
Agentless discovery works best when the scanner can reach the device. If a laptop leaves the office network and is not reachable through a VPN or another connected network, the scanner may no longer be able to query it.
Agent-based discovery does not depend on the device remaining on the same local network. A laptop can continue sending information while the employee works from home, another office, or while traveling. It only needs to be able to connect to the central platform.
→ Agent-based discovery is usually better for remote and mobile endpoints.
Continuous Monitoring and Updates
Agentless discovery normally updates information when another scan runs. If scans happen daily, weekly, or manually, changes between scans may not immediately appear in the inventory. The frequency may depend on network size, scan duration, and the amount of traffic generated.
Agent-based discovery can report information directly from the endpoint on a regular schedule. Some agents can also report certain changes when they happen, depending on the product. This makes agent-based discovery better suited to environments where endpoint information changes frequently.
→ Agentless discovery is a better fit when scheduled scans are enough to keep inventory reasonably current. Agent-based discovery is better when device changes need to be reported more frequently, especially across remote endpoints.
Maintenance
Agentless discovery removes the need to maintain software on every endpoint. IT teams mainly manage the scanner, discovery configuration, credentials, network ranges, and protocol access.
Agent-based discovery introduces another software component on each managed device. Agents may need to be deployed, updated, monitored, or repaired when they stop reporting correctly.
→ Agentless discovery reduces endpoint maintenance, while agent-based discovery adds an agent lifecycle that IT needs to manage.
4. When To Use Each Type
The right discovery method depends on what devices you need to find, where those devices are located, and how much detail you need to collect.
In many environments, the choice is not simply agentless or agent-based. Each approach is better suited to a different discovery need.
When To Use Agentless Discovery
Agentless discovery is a good fit when your main goal is to find what is connected to the network.
It is especially useful when:
- Find unknown or unmanaged devices
- Build or validate an asset inventory
- Discover printers, switches, routers, IoT devices, and other assets that cannot run an agent
- Avoid installing software on every endpoint
- Run periodic network checks
For example, an IT team responsible for an office network may use agentless discovery to scan each subnet regularly. This helps them identify new devices, compare discovered devices against the asset inventory, and investigate anything they do not recognize.
When To Use Agent-Based Discovery
Agent-based discovery is a better fit when your main goal is to maintain detailed and ongoing visibility into managed endpoints.
It is especially useful when:
- Track remote or mobile laptops
- Collect deeper endpoint information
- Keep device records updated more frequently
- Monitor managed laptops, desktops, and servers
- Maintain visibility when devices move between networks
For example, a company with a remote workforce may install discovery agents on employee laptops. The agents can continue reporting device information even when employees rarely connect to the corporate network.
When To Use Both
For many IT environments, combining both approaches provides the most complete coverage. Agentless discovery can help IT teams find devices across the network, including unknown devices and equipment that cannot run an agent. Agent-based discovery can then provide deeper and more continuous information for managed laptops, desktops, and servers.
A common approach is to use agentless discovery first to find devices across the network. Then deploy agents only to the endpoints that need deeper or more frequent monitoring. Keep running agentless scans to catch new or unmanaged devices.
FAQs
1. Does agentless discovery affect network performance?
It can, depending on the size of the scan, the protocols used, and how aggressively the scanner is configured. In larger environments, IT teams often control scan ranges, concurrency, and schedules to avoid unnecessary network load.
2. How often should you run agentless discovery scans?
There is no single schedule that works for every environment. Stable office networks may only need periodic scans, while networks with frequent device changes may benefit from more regular discovery. The goal is to scan often enough that your inventory does not fall significantly behind the actual environment.
3. Can agentless discovery work across multiple subnets or VLANs?
Yes, but the scanner needs network access to those segments. Routing rules, firewalls, and VLAN configuration can affect which devices it can reach, so larger networks may require additional scanner placement or network configuration.
4. Is agentless or agent-based discovery more accurate?
Accuracy depends on what you are trying to identify. Agentless discovery can be more useful for confirming that a device exists on the network, while agents can provide more consistent endpoint information. In practice, comparing discovery data with existing asset records often gives IT teams a more reliable inventory than relying on a single source.
5. What should IT teams do with devices found through discovery?
Discovery should lead to an action, not just a list of IP addresses. Newly found devices should be matched against existing asset records, identified where possible, and reviewed if they are unknown or unmanaged. This helps turn discovery data into a more accurate IT asset inventory.
Final Thoughts
Agentless and agent-based discovery solve different visibility gaps. Use agentless discovery when you need to find what is connected, uncover unknown devices, or cover a wider mix of network assets. Use agent-based discovery when you need deeper, ongoing data from managed endpoints.
Need a clearer view of what is connected to your network? Start with the AssetLoom Free Network Scanner to discover devices without deploying agents first.
