Network visibility lets the IT and OT sensors in a Network Discovery group detect assets passively, without scanning them. It's enabled by default and configured per group, in the same place as the group's update schedule.
What network visibility does
When network visibility is enabled, sensors put their network interfaces into promiscuous mode and parse the broadcast traffic they observe, reading the source and destination MAC and IP addresses. Addresses that don't match an existing asset are added to your inventory as new assets.
This happens continuously and independently of your discovery actions. A device is detected as soon as it communicates on a segment one of your sensors can see, even when it falls outside the targets of every action and doesn't respond to active scans.
Passive detection tells you that a device exists. It can't tell you what the device is: that needs an active scan, ideally with credentials.
Network visibility compared to the traffic sensor
Both methods are passive, but they're separate features with different requirements.
| Network visibility | Traffic sensor | |
|---|---|---|
| Runs on | The IT and OT sensors already in the group | A separate traffic sensor you install |
| Network configuration | None | Traffic delivered through SPAN, RSPAN, ERSPAN, TAPs, or packet brokers |
| Reads | Broadcast traffic on the sensor's own interfaces | Mirrored or forwarded traffic |
| Tells you | That a device exists, by MAC and IP address | Which assets exist, plus application dependencies, service relationships, and east-west traffic patterns |
For the traffic sensor, see Discover assets with the traffic sensor.
Turn network visibility on or off
We recommend leaving network visibility enabled, so you also get coverage of assets that don't respond to active scans.
- In your Lansweeper Site, go to Discovery > Groups.
- Select the Network Discovery group you want to change. By default, all Network Discovery hubs and sensors belong to Default Group Network Discovery.
- Turn Enable network visibility on or off. The setting applies to every sensor assigned to the group.
- Select Save changes.
The same toggle appears when you create a new group. In that flow, select Save and finish to create the group. See Update Network Discovery for the full group creation steps.
Turning off network visibility stops the group's sensors from discovering assets automatically. From then on, they only discover the targets defined in your discovery actions.
What passively detected assets look like
Passively detected assets carry only what broadcast traffic reveals, so expect the following until something identifies them further:
- Minimal detail. A MAC address and an IP address, usually with the asset type Unknown or Network device.
- Unrecognized in coverage reporting. An asset only counts as recognized once its manufacturer and model are populated and its type isn't Network Device or Unknown. Passively detected assets therefore lower your recognized coverage percentage until they're scanned. See Understand recognition coverage.
- A place in your inventory. They appear alongside actively scanned assets. See Manage your licensed asset limit for what counts toward your limit.
To identify these assets, point a discovery action with credentials at the range they're in. See Improve recognition coverage.
To control how long they stay in your inventory, use the cleanup rules for passively detected assets. See Manage asset cleanup rules.
Next steps
- Create a Network Discovery action to identify the assets network visibility finds.
- Manage asset cleanup rules to clean up passively detected assets you no longer need.