Multiple probes and groups

Summary

More networks need more probes. A probe group brings them together: one pooled licence and one scan for every site, where each probe runs its own part. In this lesson you create a group, add its members, start a group scan and read the results per probe.

Why one probe per network

A probe sees the network it sits on in full detail: it uses ARP, and ARP does not cross routers. That is why each network, or VLAN, needs its own probe: three sites with two VLANs each, for example, need six probes. Reachable routed networks can still be added to a scan, but without ARP the probe does not see the devices' MAC addresses.

Create the group and add probes

If you have more than one network, create the group first and then add the probes from inside the group. Grouping probes that are already installed is possible, but it takes more work.

1. In Internal Probes click Add probe group.
2. In the Details step enter the Group name: every probe in the group shares one pooled licence.
3. Click Create & continue to move to Members. Here you can Add an installed probe from the same company, or Install new probe: the new probe joins the group automatically.

A probe can belong to only one group, and every probe in a group must belong to the same company. From the group menu, Add / manage probes takes you back to member management.

The pooled licence

On the group card, Pooled license shows the assets used against the capacity. The count merges every probe's inventory, and a device seen by two probes counts once. If a probe with its own licence joins a licensed group, its individual licence is suspended, not deleted, and its expiry date keeps running.

Scan the group

1. From the group menu choose Run scan.
2. In the Probes & networks step pick the networks each probe should scan: every probe runs its own slice of one shared scan. Click Continue.
3. In Review, the Scan plan summarises the probes and the group's pooled licence. Click Start scan (the button shows the number of probes).

Offline probes are skipped and only online probes scan, unless you choose to include them anyway.

Results per probe

Every probe stays visible in the results: in Overview the Probes card lists the probes that took part, and in Asset Inventory the Found by filter shows which probe found each device.

Chapters

Key points

• One probe per network or VLAN: ARP does not cross routers.
• With several networks, create the group first and add probes from inside it.
• A group has one pooled licence; a device seen by several probes counts once.
• A group scan is a single scan: each probe scans the networks chosen for it, and results stay attributed to the probe that found each device.
• If the VLANs live on the same switch there is an alternative: one machine on an 802.1Q trunk port, with one tagged interface per VLAN, and the VLAN networks added to the probe's networks. It works, but one probe per VLAN, grouped together, stays clearer. Your network team configures trunk ports and VLANs.

Transcript

The full transcript of the video (in Italian) is in the player's Transcript tab.

Next steps