An air-gapped network is a completely isolated system that physically and digitally protect your most important assets. Hackers simply can’t get in because there’s no way to reach them from the outside world.
It’s why the military uses air-gapped networks to protect classified information. Why financial institutions rely on them to secure their most sensitive transactions. And why more businesses are turning to air-gapped systems to protect their critical data backups.
But what exactly is an air-gapped network, and why should you care? At its core, it’s exactly what it sounds like—a network with literal air between it and the outside world. No wireless connections, no internet access, no external links whatsoever. This physical separation creates an impenetrable barrier that makes air-gapped systems one of the most effective security measures available today.
Below, we’ll explain what these air-gapped networks are, how they work, and how they might be the missing piece in your organization’s cyber resilience strategy.
What Is an Air-Gapped Network?
An air-gapped network is a computer network that’s physically separated from all other networks, including the internet, local networks, and even other air-gapped systems.
There’s literal air between it and other networks. No ethernet cables connecting to external systems, no Wi-Fi or Bluetooth capabilities, no cellular or radio connections. Nothing. This complete physical isolation is what makes air-gapped networks one of the most secure ways to protect sensitive data and critical systems:
- Physical Separation: The defining feature of an air-gapped network is its complete physical isolation. Any computer or device on the network is dedicated solely to that network—no dual connections, no temporary links, no exceptions.
- Controlled Data Transfer: When data needs to move in or out of an air-gapped network, it happens through strictly controlled methods. This might mean using designated USB drives (often called “data diodes” because they only work in one direction), or specialized hardware that guarantees secure, one-way information flow.
- Dedicated Hardware: Every device on an air-gapped network—from computers and servers to printers and storage systems—is purpose-built for that network. You can’t just take a regular laptop, disconnect it from the internet, and call it air-gapped. The hardware itself needs to be configured specifically for isolated operation.
While most networks are built to facilitate connections, an air-gapped network is intentionally designed to prevent them. It’s this fundamental difference in philosophy that makes air-gapped systems uniquely effective at protecting critical data and systems from cyber threats.
Benefits of an Air-Gapped Network
The benefits of an air-gapped network go far beyond just “good security.” Cyber attacks are becoming more sophisticated and costly, and air-gapped networks offer distinct advantages that other security measures simply can’t match:
- Complete Against Remote Attacks: No internet connection means no remote access, period. Hackers can’t breach what they can’t reach, making air-gapped networks immune to ransomware, malware, and other remote cyber attacks that plague internet-connected systems.
- Guaranteed Data Recovery: When your backups are air-gapped, they’re completely isolated from your production environment. Even if your main systems are compromised, your air-gapped backups remain clean and ready for recovery—no ransom payments necessary.
- Simplified Compliance: Many regulatory frameworks like HIPAA, CMMC, and FedRAMP specifically recommend or require air-gapped systems for certain types of data.
- Protected Operations: For systems that absolutely cannot fail—think power grids, industrial controls, or financial systems—air-gapped networks provide unmatched reliability. They continue operating normally even during widespread cyber attacks because they’re completely disconnected from vulnerable networks.
- Complete Control Over Data Flow: With an air-gapped network, nothing moves in or out without your explicit action and approval. This level of control means you always know exactly what’s happening with your sensitive data and systems.
- Improved Incident Response: If you experience a cyber attack, having air-gapped backups means you can recover quickly and completely. There’s no uncertainty about whether your backups are compromised because they’re physically impossible to reach from the affected systems.
- Future-Proof Security: While cybersecurity threats evolve constantly, the principle of physical separation remains effective. Air-gapped networks provide protection not just against today’s threats, but against future attack methods that haven’t been invented yet.
Common Use Cases of Air-Gapped Networks
Air-gapped networks aren’t just for government agencies anymore. Organizations across industries are discovering that air-gapped systems provide the ultimate protection for their most critical assets:
- Backup and Disaster Recovery: The most rapidly growing use case for air-gapped networks is protecting backup systems. When ransomware strikes, attackers typically try to encrypt or delete backups to force ransom payments. Air-gapped backups remain completely safe and ready for recovery, giving organizations a guaranteed way to restore operations without paying ransoms.
- Financial Systems: Banks and financial institutions use air-gapped networks to protect core banking systems and transaction data. These networks gurantee that even if public-facing systems are compromised, the critical financial infrastructure remains secure and operational.
- Healthcare Operations: Hospitals and healthcare providers rely on air-gapped networks to protect patient data and critical care systems. With lives literally on the line, these organizations can’t risk their essential systems being compromised by cyber attacks.
- Industrial Control Systems: Manufacturing facilities, power plants, and other industrial operations use air-gapped networks to protect their control systems. This separation guarantees production can continue even during cyber attacks.
- Research and Development: Companies developing new products or technologies often use air-gapped networks to protect their intellectual property. This approach prevents corporate espionage and protects valuable research data.
- Military and Defense: Military organizations worldwide use air-gapped networks to protect classified information and critical defense systems.
- Government Operations: Federal, state, and local governments use air-gapped networks to protect citizen data and critical infrastructure. This separation helps prevent both criminal attacks and state-sponsored cyber warfare attempts.
How Air-Gapped Networks Work
The beauty of an air-gapped network lies in its simplicity: create a secure environment, physically isolate it, and strictly control how data moves in and out. That’s it. Here’s how it works in practice.
Physical Infrastructure
An air-gapped network consists of the same components as any other network: servers, workstations, storage devices, and internal networking equipment. However, every piece of hardware is dedicated solely to the air-gapped environment. These systems are typically housed in secure, access-controlled locations with comprehensive physical security measures—think biometric access controls, security cameras, and 24/7 monitoring.
Data Transfer Protocols
Since there’s no direct connection to external networks, data movement follows strict protocols:
- Authorized Transfer Devices: Organizations use specifically designated, heavily secured USB drives or external hard drives for data transfers. These devices are never used on any other network.
- One-Way Data Flow: Many organizations implement “data diodes”—hardware devices that physically enforce one-way data transfer.
- Security Scanning: Before any data enters the air-gapped network, it goes through extensive security scanning in an isolated quarantine environment to detect any potential threats.
Access Control and Security
Human access to air-gapped networks requires multiple layers of authentication and verification. Every interaction with the system is carefully logged and monitored with regular security audits to guarantee the network’s integrity. Personnel must complete specialized training before gaining access, and permissions are regularly reviewed to maintain strict control over who can interact with the system.
Maintenance and Updates
Keeping air-gapped systems current requires a methodical approach. Updates undergo thorough security scanning on separate systems before being transferred through authorized channels. System administrators perform all maintenance during scheduled windows to carefully document each change and verify system integrity afterward.
This combination of physical separation, strict protocols, and careful maintenance creates an environment where critical data and systems remain completely protected from external threats.
9 Best Practices for Implementation
While the concept might be straightforward—physically isolate a network from external connections—proper execution demands careful planning and strict adherence to security protocols. Here are the best practices that make the difference between a secure air-gapped network and one that just looks good on paper:
1. Start with a Security Assessment:
Map out exactly what needs protection and why. Identify your most critical data, systems, and assets to determine the scope of your air-gapped network.
2. Implement Strict Hardware Controls:
Use only dedicated, purpose-built hardware for your air-gapped network. Remove or physically disable all wireless capabilities, including WiFi cards, Bluetooth modules, and cellular modems. Even seemingly innocuous features like infrared ports should be eliminated.
3. Establish Clear Data Transfer Procedures:
Create detailed protocols for moving data in and out of the network. Designate specific transfer devices, implement thorough scanning procedures, and maintain careful logs of all data movements. Consider implementing one-way data diodes for additional security.
4. Design for Physical Security:
House air-gapped systems in access-controlled spaces with 24/7 monitoring. Use security cameras, biometric access controls, and maintain detailed logs of who enters and exits. Consider environmental controls to protect against physical threats like fire or water damage.
5. Create Redundant Backup Systems:
Even air-gapped networks need backups. Implement a separate air-gapped backup system that maintains copies of critical data while following the same strict security protocols as your primary network.
6. Develop Comprehensive Training Programs:
Every person who interacts with the air-gapped network needs thorough training on security protocols and procedures. This includes IT staff and any executives or employees who need access to the system.
7. Establish Incident Response Plans:
While air-gapped networks are highly secure, you still need procedures for handling potential security incidents. Document response procedures for various scenarios, from attempted breaches to hardware failures.
8. Implement Regular Auditing:
Conduct periodic security audits to verify the network’s integrity. This includes physical security checks, access log reviews, and testing to confirm the network remains truly air-gapped.
9. Plan for Maintenance and Updates:
Create specific procedures for handling system updates and maintenance. Include protocols for verifying updates, testing them in a separate environment, and safely transferring them to the air-gapped network.
Protect Your Critical Data with Airiam
Implementing and maintaining an air-gapped network might sound daunting—and truthfully, it is. The technical requirements, security protocols, and ongoing maintenance demand major expertise and resources.
Fortunately, you don’t have to figure this out alone. At Airiam, we’ve spent years perfecting air-gapped backup solutions through our AirGapd™ service. We handle everything from architecture and deployment to configuration and recovery to guarantee your critical data stays completely protected from cyber threats.
Our approach goes beyond basic air-gapped storage. We physically separate your immutable backups from your network and backup servers, encrypt all data using AES 256-bit encryption, and transmit via TLS 1.2 to keep your information safe during transit and at rest. More importantly, we hold the encryption keys—meaning hackers can never steal them from you, even if they breach your primary systems.
The best part? While we maintain bank-level security, accessing your data when you need it remains simple. Our 24/7/365 disaster recovery operations center fully manages your restoration and recovery plans. No digging around for backups or scrambling to make them live—we handle all the complexity so you can focus on running your business.
Ready to protect your critical data with a truly secure air-gapped solution? Contact Airiam today to learn how we can help make your infrastructure ransomware-resilient.
