Air-gapped patch management for Windows and Linux
Cloud patch services need the internet; enclaves cannot reach it. How to patch and prove compliance for Windows and Linux machines with no internet access, and what the management tool itself must satisfy.
Most modern patching products assume every machine can reach a cloud service: Azure Update Manager needs Azure Arc, SaaS patch tools need their portal, and even many on-prem tools phone home for licensing or content. In an air-gapped network (a classified enclave, an OT plant, a lab under export control) none of that is allowed.
The four problems an air gap creates#
- Getting content in. Updates and compliance content must cross the gap through an approved transfer process.
- Knowing what is missing. Machines cannot ask Microsoft or a distribution's servers what they need.
- Running the changes with approvals and windows, without a cloud control plane.
- Proving it, with evidence an assessor accepts and the management tool itself trusted inside the boundary.
How teams solve each one#
- Content: a local mirror of Linux repositories, and Windows updates staged on an internal share or update service, refreshed through the transfer process.
- Knowing what is missing: on Windows, a scan against Microsoft's offline update catalog tells each machine what it lacks with no internet connection; on Linux, the package manager compares against the local mirror.
- Running changes: an on-prem console that schedules patch rings inside change windows and handles reboots.
- Proof: per-machine results, a tamper-evident change log, and an export the assessor can verify on their own machine.
What the management tool must satisfy#
Inside an enclave, the patching tool is in scope too:
- Installs and runs fully offline, from a bundle you carry in, with no license server to call.
- Signed releases, with a published key, and an SBOM per image so its components can be reviewed.
- No inbound management ports on endpoints, and least privilege for people and automation.
- Commands off by default, so a compromised console cannot run arbitrary code on the fleet.
- A tamper-evident audit log that forwards to the enclave's SIEM.
How Gardience fits#
Gardience is a supported console on open-source Salt for Windows and Linux, built to run in exactly this setting:
- Installs from an offline bundle with signed releases and an SBOM per image; nothing is sent out.
- Patches Windows Server 2016 to 2025, Windows 10 and 11, and major Linux distributions; Windows machines with no internet can be scanned against Microsoft's offline catalog.
- Pilot and broad rings, change windows, locks, two-person approval, and real patching with reboots handled.
- A scored STIG/CIS-aligned baseline with drift repair on the same agents.
- A tamper-evident audit log with SIEM forwarding, and a signed evidence pack with an offline verifier.
- An optional AI assistant that works with a self-hosted model inside the enclave.
Questions#
Can Windows machines be scanned for missing updates without internet access?#
Yes, against Microsoft's offline update catalog, which can be carried into the network. Gardience runs these offline catalog scans for Windows machines with no internet.
How do Linux machines patch in an air gap?#
From a local mirror of their distribution's repositories, refreshed through your transfer process. The management tool drives the package manager and records the results.
Does Gardience need to reach the internet for licensing?#
No. It installs and runs fully offline from an offline bundle.
Try Gardience on your own machines
One supported console for Windows and Linux on open-source Salt: patching, a scored STIG/CIS-aligned baseline, drift repair, event-driven automation, two-person approval and a tamper-evident audit log. Flat yearly pricing, not per node.
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