Air gapping is a cybersecurity strategy that isolates a system or dataset from all unsecured or external networks, including the public internet and internal enterprise LANs. The objective is simple but powerful: eliminate any potential digital pathway for cyber threats to reach critical systems or data. By removing or severely limiting network connectivity, air gapped environments act as a buffer zone—protecting high-value assets from external compromise, malware propagation, or unauthorized access.
At its core, an air gap (sometimes even referred to as air wall) is a control-layer barrier that can be implemented physically (no network interface at all) or logically (strictly controlled access paths). The key difference between air gapped and non-air gapped systems is connectivity. A non-air gapped backup server might be reachable via APIs or SMB shares. An air gapped one? It doesn’t talk to anything—or only talks under very tightly regulated, monitored conditions.
This concept has long been used in military, intelligence, and critical infrastructure systems where confidentiality, integrity, and survivability are paramount. But today, it’s becoming a vital tool in commercial environments as well—especially to protect immutable backups, compliance archives, and disaster recovery assets from modern threats like ransomware.
Types of Air Gaps
Air gapping can be achieved through several architectural approaches, each with different implications for security, manageability, and operational complexity. Here’s a deeper look at the most common types:
Physical Air Gap
A physical air gap refers to a system that is completely disconnected from any network interface—wired or wireless. There are no Ethernet ports connected, no Wi-Fi radios enabled, and no route to any external or internal network. The only way to move data in or out is through removable media, such as USB drives, external hard disks, or tape. This is the most secure form of air gapping, as it offers zero digital attack surface, but it’s also the most operationally burdensome. Data transfers are slow, manual, and prone to human error. It also introduces challenges for integrity verification and automation unless additional secure controls (e.g., offline signing, checksum validation) are implemented.
Example: Critical systems in nuclear power plants often use physically air gapped networks to prevent any external communication, ensuring operational safety and regulatory compliance.
Logical Air Gap
A logical air gap maintains network connectivity but enforces strict software-defined access boundaries. These systems are segmented at the network or application layer using firewalls, VLANs, IAM policies, access control lists (ACLs), and role-based authentication. The core idea is to make the data logically unreachable from general-purpose environments. For example, backup data may reside on a system that’s in a separate security zone, only accessible via a dedicated management interface or controlled API. Logical air gaps are easier to maintain than physical ones, support automation, and scale better—but require meticulous configuration and continuous auditing to prevent accidental exposure or misconfigurations.
Example: A financial institution segments its backup infrastructure into a separate VLAN with strict ACLs, so even if the production network is compromised, the backup data remains untouched.
Network Air Gap
A network air gap separates systems by inserting controlled, one-way communication pathways between zones. These setups often include data diodes, one-directional syncs, API gateways, or read-only proxies that allow data to flow in—but not out. This limits data exfiltration or command/control backflow, which is crucial in secure environments. For example, a production system might export logs to a write-only audit archive that accepts data via a secure push mechanism, but never responds. This type of air gapping provides a balance between isolation and usability, though it typically requires specialized hardware or custom proxy configurations to enforce directional integrity.
Example: A defense contractor uses hardware data diodes to send telemetry from classified internal systems to external monitoring tools without exposing any return communication path.
Operational Air Gap
An operational air gap doesn’t rely on architecture alone—it uses time-based or process-based controls to restrict access to critical data. Systems may be kept offline or unmounted by default, only brought online during specific time windows or under manual supervision. Common implementations include scheduled firewall rules, admin-triggered mounting of secure volumes, or cron-based toggling of access points. This method is highly dependent on operational discipline and carries the risk of human error but is useful when full-time isolation isn’t practical. It’s often seen in backup workflows, where storage is only exposed briefly for data ingestion or recovery.
Example: A healthcare provider mounts its backup storage for one hour nightly, during which only backup jobs have access, and then disconnects it from the network automatically.
Soft Air Gap
A soft air gap refers to a storage system that remains accessible over the network, but implements strict immutability and policy-based protections that make it functionally resistant to tampering or deletion. This is not an air gap in the traditional sense—the data can still be accessed via APIs—but it behaves like an air gap because the data cannot be altered, overwritten, or removed during a defined retention period, even by privileged users.
This model is typically achieved using S3 Object Lock, versioning, and write-once-read-many (WORM) enforcement, often in compliance or governance mode. Once configured, retention policies ensure that data is immutable and deletion-proof, providing a strong safeguard against ransomware and insider threats—while retaining the benefits of automation and remote accessibility.
Example: A media company archives production assets to an S3-compatible object store with Object Lock enabled, ensuring that no content can be deleted or altered during the editing freeze period—even by administrators or automated systems.
Benefits of Air Gapping
Air gapping isn’t just a theoretical security model—it delivers tangible, operational value across multiple domains. When implemented correctly, it enhances not only security but also compliance posture and data durability.
- Protection Against Ransomware: Modern ransomware often seeks out backups and shadow copies to encrypt or delete them before targeting primary data. Air gapped systems, by design, are unreachable—making them immune to this kill-chain step.
- Preservation of Data Integrity: By isolating data from modification pathways, air gapping ensures that stored data remains unaltered over time. This is crucial for regulated industries and long-term archival use cases where tamper-resistance is non-negotiable.
- Resilience Against Insider Threats: Air gaps reduce the risk posed by malicious or compromised insiders by limiting the systems they can touch. With properly enforced access boundaries, even admin credentials don’t grant modification rights to air gapped data.
- Compliance with Regulatory Mandates: Frameworks like SEC 17a-4, FINRA, HIPAA, and GDPR require immutable and auditable data retention. Air gapping—especially when combined with object locking and retention policies—helps demonstrate technical compliance.
- Disaster Recovery Assurance: In the event of a widespread breach, misconfiguration, or system compromise, air gapped data serves as a clean, trusted recovery source, enabling faster and more reliable disaster recovery.
Conclusion
In a world where cyber threats increasingly bypass traditional defenses and target backup and recovery infrastructure directly, air gapping has re-emerged as a foundational layer of cyber resilience. Whether implemented physically, logically, or through policy-enforced immutability, the goal remains the same: ensure critical data is shielded from compromise, corruption, or deletion—even in the worst-case scenario.
Designing an effective airgap strategy requires balancing security, automation, and operational agility. This is where software-defined storage systems like DataCore Swarm come into play. As an on-premises, S3-compatible object storage platform, Swarm supports the core principles of air gapping through immutable object locking, fine-grained access control, and network segmentation—enabling organizations to build airgap-like protections without sacrificing scale or efficiency.
Ultimately, air gapping isn’t just about isolation—it’s about survivability. And in today’s threat landscape, that could make all the difference.
