Stateful Firewalling (EN)

Stateful Firewalling

Stateful Firewalling is a firewall technique that tracks the state of network connections and automatically allows existing connections, even if they are not explicitly listed in the firewall rules. This method improves performance and usability since a new rule doesn't need to be created for every data packet communication. It is a standard feature of modern firewalls.

Data Flow

flowchart TD     A[Client] -->|SYN| B[Stateful Firewall]     B -->|SYN/ACK| C[Server]     C -->|ACK| B     B -->|Connection allowed| A     A -->|Data packets| B     B -->|Data packets| C     C -->|Data packets| B     B -->|Data packets| A     A -->|FIN| B     B -->|FIN/ACK| C     C -->|ACK| B     B -->|Connection ended| A 

In Context

• Typically compared with Stateless Firewalling
• Related to: Deep Packet Inspection, Next-Generation Firewall
• Example use: Protection of corporate networks from unauthorized access