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Licensing without internet (air-gapped)

Understand's default online licensing needs to reach licensing.scitools.com. On a disconnected machine you use one of three approaches that need no internet from the target. This page picks the right one for an air-gapped deployment and points at the detailed walkthroughs — it doesn't repeat the step-by-step.

Which license do I have?

The right method depends on your license type. See Which license do I have? first if you're unsure whether you have a floating (online), node-lock, or server license.

What online licensing collects (and how to stop it)

When Understand licenses online, the licensing service records the user name, device name, and IP address so the license owner can see who is using a seat. Understand's own Privacy page states:

"Our online licensing system records the user name, device name and IP address to show the license owner who is using the license. To disable this collection, use the Offline Checkout feature of Licensing."

So the offline methods below are not just a connectivity workaround — they are also how you stop that collection.

You generate a request code in Understand, exchange it for a reply code at scitools.com/offline from any connected device, and enter the reply code back on the air-gapped machine. Nothing on the target ever contacts a server. Full walkthrough, including extend and return:

For headless/CI machines the same flow is available with und switches (-createofflinerequestcode, -setofflinereplycode … -expiration …, -showofflinereturncode).

Option 2 — Node-lock

A node-lock code locks the license to one machine and needs no server. Generate the request code, exchange it, and enter the reply code:

und -createnodelockrequestcode
# ...exchange the code with SciTools...
und -setnodelockreplycode <CODE>
und -shownodelockreturncode        # when releasing it

See Licensing from the command line for the full switch list.

Option 3 — A license server inside your network

If your organization runs its own reachable license server — SciTools' self-hosted Icarus server, which serves floating seats entirely inside your network (see Set up an on-premises license server (Icarus)) — point Understand at it instead of the default licensing.scitools.com:

und -setlicenseserver <your-host>

Or set it per-run with environment variables (they take precedence over stored settings — handy for CI runners):

Variable Effect
UNDERSTAND_LICENSE_CODE Use this license code
UNDERSTAND_LICENSE_SERVER Use this license server (highest precedence)
STI_LICENSE_SERVER Legacy server override (fallback)
UNDERSTAND_LICENSE_ALLOW_HTTP Allow plain HTTP to the license server

Details and the full command reference: Licensing from the command line.

After licensing: confirm nothing else reaches out

Licensing is only one of the optional network features. Once licensed offline, review What leaves the machine to disable analytics, update checks, and (on Windows) automatic crash reporting.