An OT firewall filters network traffic according to configurable rules. The Electronic AirGap, on the other hand, completely eliminates network connectivity between two zones. These are complementary approaches: the firewall controls traffic flows, while the Electronic AirGap removes the very possibility of unauthorized network traffic.

Why a firewall alone is not enough in OT environments

Industrial firewalls have several vulnerabilities in operational contexts:

  • They require regular updates (firmware, signatures, rules), often incompatible with maintenance windows limited to a few hours per year.
  • They rely on software and remain vulnerable to configuration errors, zero-day exploits, and attacks targeting TCP/IP layers.
  • Their effectiveness depends on the quality and constant updating of their rules.

The Electronic AirGap approach

By removing the transport and network layers through an electronic protocol break, the Electronic AirGap inherently eliminates an entire category of attacks. Maintenance is minimal: on average, one software update per year. Protection does not rely on up-to-date signatures or rule maintenance.

The Electronic AirGap does not systematically replace a firewall. It complements it within a defense-in-depth strategy, protecting the most critical perimeter—where a compromise would have major operational impact.

Key takeaway — Where a firewall filters traffic, the Electronic AirGap breaks network continuity. Both are complementary: the firewall for routine segmentation, the Electronic AirGap for isolating the most critical assets.