Die von Microsoft übernommene Whale Communications bot mit dem Intelligent Application Gateway (IAG) in bestimmten Ausbaustufen ein sogenanntes AirGap, mit dem eine physikalische Trennnung von Netzwerken erfolgen konnte.
Zum Nachfolger, dem Microsoft Intelligent Application Gateway 2007, findet man in den offiziellen FAQs zu IAG 2007 folgende Passage zur Verfügbarkeit von AirGap:
Q. What happened to AirGap?
A. ISA Server, combined with IAG 2007, serves the need for network separation and full control of inbound and outbound content and adds significant edge security functionality to address a broad set of customer requirements. The consolidated appliance provides a flexible software-driven solution that is responsive to the need for performance, management, and scalability in addition to comprehensive security. The blending of stateful packet filtering, circuit filtering, application-layer filtering, Web proxy, and endpoint security into a single appliance affords the administrator with a variety of options for configuring policy-driven solutions for access to applications and network resources.
ISA Server delivers the ability to filter traffic rather than rely on a mechanistic solution, providing three types of firewall functionality: packet filtering (also called circuit-layer), stateful filtering, and application-layer filtering. The ability to apply rule-based filtering to all traffic that traverses the network boundary enables the combined solution to directly address threats such as worms or malware that may originate from authenticated users.
The solution combines ISA’s robust IPsec and firewall security features, content inspection capabilities and Web caching features with IAG’s full-featured application-layer SSL VPN, endpoint compliance, and application security functionality to provide a cost-effective integrated network protection and remote access solution providing superior inbound and outbound security.
Eine etwas unbefriedigende Antwort auf die doch übersichtliche Frage. Deshalb eine kurze Antwort hier: Das AirGap gibt es noch. In der Network Engines Appliance NS-4700.
Weitere OEM-Hersteller von IAG-Appliances sind derzeit Celestix und Pyramid. Einen interessanter Artikel zu AirGap findet man im Übrigen in Wikipedia.