Air-Gapped Network.

A network that is physically and logically isolated from other networks, especially the internet, to protect highly sensitive systems such as ICS, classified networks, or vaults. It belongs to the OT / ICS / IoT category of cybersecurity.

A network that is physically and logically isolated from other networks, especially the internet, to protect highly sensitive systems such as ICS, classified networks, or vaults.

An air-gapped network has no direct connection to less trusted networks; data crosses the boundary only through controlled means like removable media, data diodes, or kiosk transfer stations. Air gaps are used for nuclear-plant safety systems, classified military networks, cryptocurrency cold storage, voting infrastructure, and parts of ICS, on the assumption that physical isolation forces an attacker to bridge the gap. In practice, real-world incidents (Stuxnet, agent.btz, and academic covert channels using acoustic, thermal, magnetic, or optical emanations) show that air gaps can be crossed via infected USB drives, supply chain implants, or compromised maintenance laptops. Effective programs combine air gaps with strict media-control policies, signed firmware, host-based intrusion detection, and monitoring for anomalous device or RF activity.

Defences for Air-Gapped Network typically combine technical controls and operational practices, as detailed in the full definition above.

Common alternative names include: Air gap, Isolated network, Stand-alone network.