gRPC

Mapping Logical Air Gap Techniques for Secure Network Segmentation

A detailed technical overview explores how organizations can achieve logical air gaps to isolate high-value network segments without completely severing data exchange. The article contrasts classic physical air gaps with everyday reverse proxies and introduces six distinct levels of isolation ranging from physical media to semantic validation. It evaluates each approach across three axes: whether a direct network path remains, which side initiates connections, and whether synchronous responses are possible. Practical constructions such as dual-homed hosts, message brokers, and schema-enforced proxies are examined alongside common misconceptions including reverse tunnels and port knocking. The guide emphasizes that true logical air gaps terminate sessions at an intermediary that then originates new, controlled exchanges. Real-world deployments typically combine multiple layers, such as network separation plus transport proxies plus content validation, to balance security and usability for critical environments like industrial control systems and backup repositories.