Networks & Sites

A collector only monitors the networks you assign to it. This keeps each collector focused on the equipment it can actually reach, and it’s the boundary that controls what a collector is allowed to scan and connect to.

Assign networks to a collector

1. Go to Configure → Sites & Networks.
2. Pick (or create) the site, then add a network to it — an IP range in CIDR form, such as 192.0.2.0/24 or 198.51.100.0/24.
3. Open that network and select Assign Collector, then pick the collector that should watch it.

You can see which networks are already assigned to a given collector on its Overview tab under Configure → Collectors.

The collector immediately begins watching devices within those ranges: reachability checks, metric polling, and discovery scans all stay inside the networks you assigned.

Note

If you run a discovery scan or add a device, GridNMS routes the work to whichever collector owns the matching network — so make sure the right ranges are assigned to the right collector.

Organise by site

When you monitor more than one location, give each site its own collector and assign that site’s networks to it. This keeps things tidy and ensures traffic stays local to each site.

Site	Collector	Assigned networks (example)
Headquarters	hq-collector	192.0.2.0/24
Branch — Boston	bos-collector	198.51.100.0/24
Branch — Austin	aus-collector	203.0.113.0/24

You can select the current site from the site picker at the top of GridNMS to focus dashboards, inventory, and events on one location.

Which collector handles a device?

GridNMS decides automatically, and in most cases you never have to think about it:

1. A device whose IP falls inside a network with one assigned collector is polled by that collector.
2. A device whose network has several assigned collectors is spread automatically across them, and re-balanced if one goes down.
3. A device outside every assigned network has no active-polling collector — it’s passive-only: syslog and traps sent to any collector still arrive and are ingested, but nothing checks reachability or polls it for metrics.

If you need different behavior — always use one specific collector for a network or device, or add a dedicated standby collector for failover — that’s what a Collector Profile is for. Every account starts with a default policy that handles the common case above with no setup required.

Tips

Tip

Assign only the ranges a collector truly needs. Narrow assignments make routing predictable and keep each collector’s scans scoped to the right subnets.

• Overlapping ranges across collectors can make routing ambiguous — keep assignments distinct per site.
• Adding a new subnet later? Add it under Configure → Sites & Networks and assign it to the right collector — no reinstall needed.

Related

• What Is a Collector?
• Installing a Collector
• Collector Profiles — control which collector actively polls a device, and its failover behavior.
• Network Discovery