Networking Fundamentals

Circuit-level gateways

A circuit-level gateway is a type of firewall that only checks that the initial connection between the two devices is permitted. Once that connection has been made, no further checks are carried out, and all subsequent data flowing between the devices for that specific connection are allowed to pass through uninhibited. This has the benefit of improving performance but also has the obvious concern that malicious data could be transmitted after that initial connection has been made.