How does a circuit gateway firewall operate?

A circuit gateway firewall operates by establishing a connection through which authorized users can access external networks while maintaining a secure environment. In this context, the gateway creates two separate connections: one between the user and the gateway itself and another from the gateway to the external network. This dual-connection setup allows the firewall to effectively manage traffic and maintain security protocols, ensuring that only legitimate communications are allowed through.

This method distinguishes circuit gateway firewalls from other types, such as packet filtering firewalls that operate solely at the network layer, or application gateways that work at the application layer. By establishing dual connections, circuit gateways can facilitate communication between networks while performing checks and monitoring traffic, which enhances both security and usability.