A firewall can handle traffic based on connections, in addition to a standard ACL (Access List). Each connection is assigned a state, and packets are allowed based on whether they belong to a connection that is allowed or not. This approach is much more secure than ACLs, as it allows the firewall to track the state of each connection and only allow packets that are part of an established connection.
This approach also makes the configuration of rule sets easier, as only the incoming direction needs to be configured. This is because the firewall will automatically allow returning packets for an allowed connection. Unsolicited packets with the same source and destination IPs will be blocked, regardless of their direction.
Here are some of the benefits of using connection-based firewalling:
- Increased security: Connection-based firewalling can help to prevent attacks such as SYN flooding and port scanning.
- Simplified rule sets: Only the incoming direction needs to be configured, which makes rule sets easier to manage.
- Improved performance: Connection-based firewalling can improve performance by reducing the number of packets that need to be inspected.
Overall, connection-based firewalling is a more secure and efficient way to manage firewall traffic.
Here are some additional details about connection-based firewalling:
- The firewall keeps track of the state of each connection, such as the source and destination IP addresses, ports, and the direction of the traffic.
- When a new connection is established, the firewall creates a state table entry for the connection.
- The firewall allows packets that are part of an established connection.
- The firewall blocks packets that are not part of an established connection.
- The firewall can also track the state of connections that are in the process of being terminated.
Connection-based firewalling is a more complex approach than ACL-based firewalling, but it offers several advantages in terms of security and performance.
